{"id":21914,"date":"2023-01-23T15:00:01","date_gmt":"2023-01-23T14:00:01","guid":{"rendered":"https:\/\/www.dbi-services.com\/blog\/?p=21914"},"modified":"2023-01-24T13:07:36","modified_gmt":"2023-01-24T12:07:36","slug":"configuring-a-smtp-relay-on-oracle-linux-server-v8","status":"publish","type":"post","link":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/","title":{"rendered":"Configuring a SMTP relay on Oracle Linux Server v8"},"content":{"rendered":"\n<p>For some internal DMK (<a href=\"https:\/\/www.dbi-services.com\/fr\/produits\/dmk-management-kit\/\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/www.dbi-services.com\/fr\/produits\/dmk-management-kit\/<\/a>) development I had to configure a SMTP relay on my VM. Purpose of the SMTP relay is to send the email locally from DMK without any authentication. This Email will be transferred to the SMTP server created by one of my colleague on our AWS Cloud. This SMTP server is of course using authentication. To do so I have been installing and configuring postfix. Through this blog, I have just wanted to share my experience on this installation, hoping it might help someone.<\/p>\n\n\n\n<!--more-->\n\n\n\n<h2 class=\"wp-block-heading\">Installation of postfix<\/h2>\n\n\n\n<p>My lab is running Oracle Linux Server release 8.6.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# cat \/etc\/oracle-release\nOracle Linux Server release 8.6\n<\/pre>\n<\/br>\n\n\n\n<p>I have no postfix currently installed on my VM.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# rpm -qa | grep postfix\n<\/pre>\n<\/br>\n\n\n\n<p>I installed it.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# dnf install -y postfix\nLast metadata expiration check: 0:09:18 ago on Mon 23 Jan 2023 09:13:46 AM CET.\nDependencies resolved.\n==============================================================================================================================================================================================================================\n Package                                           Architecture                                     Version                                                 Repository                                                   Size\n==============================================================================================================================================================================================================================\nInstalling:\n postfix                                           x86_64                                           2:3.5.8-4.el8                                           ol8_baseos_latest                                           1.5 M\nInstalling dependencies:\n libicu                                            x86_64                                           60.3-2.el8_1                                            ol8_baseos_latest                                           8.8 M\nTransaction Summary\n==============================================================================================================================================================================================================================\nInstall  2 Packages\nTotal download size: 10 M\nInstalled size: 36 M\nDownloading Packages:\n(1\/2): postfix-3.5.8-4.el8.x86_64.rpm                                                                                                                                                          15 MB\/s | 1.5 MB     00:00\n(2\/2): libicu-60.3-2.el8_1.x86_64.rpm                                                                                                                                                          33 MB\/s | 8.8 MB     00:00\n------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------\nTotal                                                                                                                                                                                          38 MB\/s |  10 MB     00:00\nRunning transaction check\nTransaction check succeeded.\nRunning transaction test\nTransaction test succeeded.\nRunning transaction\n  Preparing        :                                                                                                                                                                                                      1\/1\n  Installing       : libicu-60.3-2.el8_1.x86_64                                                                                                                                                                           1\/2\n  Running scriptlet: libicu-60.3-2.el8_1.x86_64                                                                                                                                                                           1\/2\n  Running scriptlet: postfix-2:3.5.8-4.el8.x86_64                                                                                                                                                                         2\/2\n  Installing       : postfix-2:3.5.8-4.el8.x86_64                                                                                                                                                                         2\/2\n  Running scriptlet: postfix-2:3.5.8-4.el8.x86_64                                                                                                                                                                         2\/2\n  Verifying        : libicu-60.3-2.el8_1.x86_64                                                                                                                                                                           1\/2\n  Verifying        : postfix-2:3.5.8-4.el8.x86_64                                                                                                                                                                         2\/2\nInstalled:\n  libicu-60.3-2.el8_1.x86_64                                                                                   postfix-2:3.5.8-4.el8.x86_64\nComplete!\n<\/pre>\n<\/br>\n\n\n\n<p>The appropriate package has been installed.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# rpm -qa | grep postfix\npostfix-3.5.8-4.el8.x86_64\n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">Firewall configuration<\/h2>\n\n\n\n<p>If running a local firewall, this one needs to be configured to allow SMTP traffic.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1,4]\">\n[root@srv-ol8-ora ~]# firewall-cmd --zone=public --add-service=smtp --permanent\nsuccess\n[root@srv-ol8-ora ~]# firewall-cmd --reload\nsuccess\n<\/pre>\n<\/br>\n\n\n\n<p>Or if the firewall is not needed, which is the case on my side, I have simply deactivated it.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1,3]\">\n[root@srv-ol8-ora postfix]# systemctl stop firewalld\n[root@srv-ol8-ora postfix]# systemctl disable firewalld\nRemoved \/etc\/systemd\/system\/multi-user.target.wants\/firewalld.service.\nRemoved \/etc\/systemd\/system\/dbus-org.fedoraproject.FirewallD1.service.\n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">Remove sendmail<\/h2>\n\n\n\n<p>If installed, sendmail should be removed as per oracle documentation :&nbsp;<a href=\"https:\/\/docs.oracle.com\/en\/learn\/oracle-linux-postfix\/#introduction\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/docs.oracle.com\/en\/learn\/oracle-linux-postfix\/#introduction<\/a><\/p>\n\n\n\n<p>On my lab VM, sendmail is not installed.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# rpm -qa | grep sendmail\n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">Set Postfix as the default Mail Transfer Agent<\/h2>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# alternatives --set mta \/usr\/sbin\/sendmail.postfix\n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">Enable and start the Postfix service<\/h2>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# systemctl enable --now postfix\nCreated symlink \/etc\/systemd\/system\/multi-user.target.wants\/postfix.service \u2192 \/usr\/lib\/systemd\/system\/postfix.service.\n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">Install SASL<\/h2>\n\n\n\n<p>SASL (Simple Authentication and Security Layer) is mandatory to be used in the Postfix SMTP client.<\/p>\n\n\n\n<p>We need both following packages : cyrus-sasl cyrus-sasl-plain. I checked which cyrus packages are already installed and available.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora postfix]# dnf list cyrus-sasl cyrus-sasl-lib cyrus-sasl-plain\nLast metadata expiration check: 1:59:10 ago on Mon 23 Jan 2023 09:13:46 AM CET.\nInstalled Packages\ncyrus-sasl-lib.x86_64                                                                                     2.1.27-6.el8_5                                                                                    @ol8_baseos_latest\nAvailable Packages\ncyrus-sasl.i686                                                                                           2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl.src                                                                                            2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl.src                                                                                            2.1.27-6.el8_5                                                                                    ol8_appstream\ncyrus-sasl.x86_64                                                                                         2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl-lib.i686                                                                                       2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl-plain.i686                                                                                     2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl-plain.x86_64                                                                                   2.1.27-6.el8_5                                       \n<\/pre>\n<\/br>\n\n\n\n<p>I have installed both needed packages.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora postfix]# dnf install cyrus-sasl cyrus-sasl-plain\nLast metadata expiration check: 1:59:36 ago on Mon 23 Jan 2023 09:13:46 AM CET.\nDependencies resolved.\n==============================================================================================================================================================================================================================\n Package                                                 Architecture                                  Version                                                 Repository                                                Size\n==============================================================================================================================================================================================================================\nInstalling:\n cyrus-sasl                                              x86_64                                        2.1.27-6.el8_5                                          ol8_baseos_latest                                         96 k\n cyrus-sasl-plain                                        x86_64                                        2.1.27-6.el8_5                                          ol8_baseos_latest                                         47 k\nTransaction Summary\n==============================================================================================================================================================================================================================\nInstall  2 Packages\nTotal download size: 144 k\nInstalled size: 194 k\nIs this ok [y\/N]: y\nDownloading Packages:\n(1\/2): cyrus-sasl-plain-2.1.27-6.el8_5.x86_64.rpm                                                                                                                                             946 kB\/s |  47 kB     00:00\n(2\/2): cyrus-sasl-2.1.27-6.el8_5.x86_64.rpm                                                                                                                                                   1.6 MB\/s |  96 kB     00:00\n------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------\nTotal                                                                                                                                                                                         2.2 MB\/s | 144 kB     00:00\nRunning transaction check\nTransaction check succeeded.\nRunning transaction test\nTransaction test succeeded.\nRunning transaction\n  Preparing        :                                                                                                                                                                                                      1\/1\n  Installing       : cyrus-sasl-plain-2.1.27-6.el8_5.x86_64                                                                                                                                                               1\/2\n  Running scriptlet: cyrus-sasl-2.1.27-6.el8_5.x86_64                                                                                                                                                                     2\/2\n  Installing       : cyrus-sasl-2.1.27-6.el8_5.x86_64                                                                                                                                                                     2\/2\n  Running scriptlet: cyrus-sasl-2.1.27-6.el8_5.x86_64                                                                                                                                                                     2\/2\n  Verifying        : cyrus-sasl-2.1.27-6.el8_5.x86_64                                                                                                                                                                     1\/2\n  Verifying        : cyrus-sasl-plain-2.1.27-6.el8_5.x86_64                                                                                                                                                               2\/2\nInstalled:\n  cyrus-sasl-2.1.27-6.el8_5.x86_64                                                                           cyrus-sasl-plain-2.1.27-6.el8_5.x86_64\nComplete!                                     \n<\/pre>\n<\/br>\n\n\n\n<p>Checking&#8230;<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora postfix]# dnf list cyrus-sasl cyrus-sasl-lib cyrus-sasl-plain\nLast metadata expiration check: 1:59:46 ago on Mon 23 Jan 2023 09:13:46 AM CET.\nInstalled Packages\ncyrus-sasl.x86_64                                                                                         2.1.27-6.el8_5                                                                                    @ol8_baseos_latest\ncyrus-sasl-lib.x86_64                                                                                     2.1.27-6.el8_5                                                                                    @ol8_baseos_latest\ncyrus-sasl-plain.x86_64                                                                                   2.1.27-6.el8_5                                                                                    @ol8_baseos_latest\nAvailable Packages\ncyrus-sasl.i686                                                                                           2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl.src                                                                                            2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl.src                                                                                            2.1.27-6.el8_5                                                                                    ol8_appstream\ncyrus-sasl-lib.i686                                                                                       2.1.27-6.el8_5                                                                                    ol8_baseos_latest\ncyrus-sasl-plain.i686                                                                                     2.1.27-6.el8_5                                                                                    ol8_baseos_latest                                  \n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">Configure postfix<\/h2>\n\n\n\n<p>I have added following needed parameter to the postfix configuration, including the SMTP server name and a reference to a file (sasl_passwd) storing the username and password.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1,2,3,4,5,6]\">\n[root@srv-ol8-ora ~]# postconf -e \"relayhost = [email-smtp.eu-central-1.amazonaws.com]:587\"\n[root@srv-ol8-ora ~]# postconf -e \"smtp_sasl_auth_enable = yes\"\n[root@srv-ol8-ora ~]# postconf -e \"smtp_sasl_password_maps = hash:\/etc\/postfix\/sasl_passwd\"\n[root@srv-ol8-ora ~]# postconf -e \"smtp_sasl_security_options = noanonymous\"\n[root@srv-ol8-ora ~]# postconf -e \"smtp_sasl_tls_security_options = noanonymous\"\n[root@srv-ol8-ora ~]# postconf -e \"smtp_use_tls = yes\"                                                                                  ol8_baseos_latest                                  \n<\/pre>\n<\/br>\n\n\n\n<p>I have created the file storing the username and password for sending emails. The file is called sasl_passwd in stored in \/etc\/postfix. The format is [&lt;smtp_server_name&gt;]:&lt;port&gt; &lt;username&gt;:&lt;password&gt;.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1,2]\">\n[root@srv-ol8-ora ~]# vi \/etc\/postfix\/sasl_passwd\n[root@srv-ol8-ora ~]# cat \/etc\/postfix\/sasl_passwd\n[email-smtp.eu-central-1.amazonaws.com]:587 A*****************H:B******************z\n<\/pre>\n<\/br>\n\n\n\n<p>I have change file permission<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# chmod 600 \/etc\/postfix\/sasl_passwd\n<\/pre>\n<\/br>\n\n\n\n<p>I have run postmap on the file so it will create a database-like file so postfix can read it.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# postmap \/etc\/postfix\/sasl_passwd\n<\/pre>\n<\/br>\n\n\n\n<p>And finally reload postfix configuration.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# postfix reload\npostfix\/postfix-script: refreshing the Postfix mail system\n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">Test<\/h2>\n\n\n\n<p>In order to run test, I have installed mailx.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1,7]\">\n[root@srv-ol8-ora ~]# dnf list mailx\nLast metadata expiration check: 0:52:42 ago on Mon 23 Jan 2023 09:13:46 AM CET.\nAvailable Packages\nmailx.src                                                                                              12.5-29.el8                                                                                           ol8_baseos_latest\nmailx.x86_64 \n                                                                                          12.5-29.el8                                                                                           ol8_baseos_latest\n[root@srv-ol8-ora ~]# dnf install mailx\nLast metadata expiration check: 0:52:56 ago on Mon 23 Jan 2023 09:13:46 AM CET.\nDependencies resolved.\n==============================================================================================================================================================================================================================\n Package                                          Architecture                                      Version                                                Repository                                                    Size\n==============================================================================================================================================================================================================================\nInstalling:\n mailx                                            x86_64                                            12.5-29.el8                                            ol8_baseos_latest                                            257 k\nTransaction Summary\n==============================================================================================================================================================================================================================\nInstall  1 Package\nTotal download size: 257 k\nInstalled size: 491 k\nIs this ok [y\/N]: y\nDownloading Packages:\nmailx-12.5-29.el8.x86_64.rpm                                                                                                                                                                  5.1 MB\/s | 257 kB     00:00\n------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------\nTotal                                                                                                                                                                                         4.7 MB\/s | 257 kB     00:00\nRunning transaction check\nTransaction check succeeded.\nRunning transaction test\nTransaction test succeeded.\nRunning transaction\n  Preparing        :                                                                                                                                                                                                      1\/1\n  Installing       : mailx-12.5-29.el8.x86_64                                                                                                                                                                             1\/1\n  Running scriptlet: mailx-12.5-29.el8.x86_64                                                                                                                                                                             1\/1\n  Verifying        : mailx-12.5-29.el8.x86_64                                                                                                                                                                             1\/1\nInstalled:\n  mailx-12.5-29.el8.x86_64\nComplete!\n<\/pre>\n<\/br>\n\n\n\n<p>I ran a test sending an email to my email address.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# echo \"This is a DMK test through SMTP relay.\" | mailx -s \"DMK test\" marc.wagner@dbi-services.com\n<\/pre>\n<\/br>\n\n\n\n<p>I checked the log file.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1,5]\">\n[root@srv-ol8-ora ~]# tail -f \/var\/log\/maillog\nJan 23 11:18:32 srv-ol8-ora postfix\/pickup[47181]: 09472140C214: uid=0 from=\nJan 23 11:18:32 srv-ol8-ora postfix\/cleanup[47187]: 09472140C214: message-id=\nJan 23 11:18:32 srv-ol8-ora postfix\/qmgr[47182]: 09472140C214: from=, size=512, nrcpt=1 (queue active)\nJan 23 11:18:32 srv-ol8-ora postfix\/smtp[47184]: 09472140C214: to=, relay=email-smtp.eu-central-1.amazonaws.com[3.74.180.161]:587, delay=0.24, delays=0.01\/0\/0.14\/0.1, dsn=5.0.0, status=bounced (host email-smtp.eu-central-1.amazonaws.com[3.74.180.161] said: 554 Message rejected: Email address is not verified. The following identities failed the check in region EU-CENTRAL-1: root@srv-ol8-ora.localdomain, root  (in reply to end of DATA command))\nJan 23 11:18:32 srv-ol8-ora postfix\/cleanup[47187]: 44B7C140C22A: message-id=\nJan 23 11:18:32 srv-ol8-ora postfix\/bounce[47186]: 09472140C214: sender non-delivery notification: 44B7C140C22A\nJan 23 11:18:32 srv-ol8-ora postfix\/qmgr[47182]: 44B7C140C22A: from=, size=3090, nrcpt=1 (queue active)\nJan 23 11:18:32 srv-ol8-ora postfix\/qmgr[47182]: 09472140C214: removed\nJan 23 11:18:32 srv-ol8-ora postfix\/local[47188]: 44B7C140C22A: to=, relay=local, delay=0.01, delays=0\/0\/0\/0, dsn=2.0.0, status=sent (delivered to mailbox)\nJan 23 11:18:32 srv-ol8-ora postfix\/qmgr[47182]: 44B7C140C22A: removed\n<\/pre>\n<\/br>\n\n\n\n<p>The problem comes from the fact that the sender email address, root@srv-ol8-ora.localdomain, is not authorized on the AWS SMTP server. Using option -r in the mailx command will not help, as not working with SMTP. And in any case, I would have the same problem with DMK sending an email.<\/p>\n\n\n\n<p>This is why I had to change the sender in the postfix configuration.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Changing sender in the postfix configuration<\/h2>\n\n\n\n<p>To do so I have created a new configuration file, sender_email, in \/etc\/postfix mapping the sender email address. This file has been added to the postfix configuration at the ender_canonical_maps parameter.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1,3,7,9,11]\">\n[root@srv-ol8-ora postfix]# vi sender_email\n[root@srv-ol8-ora postfix]# cat sender_email\nroot@srv-ol8-ora.localdomain marc.wagner@dbi-services.com\noracle@srv-ol8-ora.localdomain marc.wagner@dbi-services.com\n[root@srv-ol8-ora postfix]# postconf -e \"sender_canonical_maps = hash:\/etc\/postfix\/sender_email\"\n[root@srv-ol8-ora postfix]# postmap \/etc\/postfix\/sender_email\n[root@srv-ol8-ora postfix]# postfix reload\npostfix\/postfix-script: refreshing the Postfix mail system\n<\/pre>\n<\/br>\n\n\n\n<h2 class=\"wp-block-heading\">New test<\/h2>\n\n\n\n<p>I ran a mailx command again.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# echo \"This is a DMK test through SMTP relay.\" | mailx -s \"DMK test\" marc.wagner@dbi-services.com\n<\/pre>\n<\/br>\n\n\n\n<p>And checked the log file again.<\/p>\n\n\n\n<pre class=\"brush: sql; gutter: true; first-line: 1; highlight: [1]\">\n[root@srv-ol8-ora ~]# tail -f \/var\/log\/maillog\nJan 23 12:02:45 srv-ol8-ora postfix\/pickup[57484]: 46AC1140C215: uid=0 from=\nJan 23 12:02:45 srv-ol8-ora postfix\/cleanup[57682]: 46AC1140C215: message-id=\nJan 23 12:02:45 srv-ol8-ora postfix\/qmgr[57485]: 46AC1140C215: from=, size=508, nrcpt=1 (queue active)\nJan 23 12:02:45 srv-ol8-ora postfix\/smtp[57684]: 46AC1140C215: to=, relay=email-smtp.eu-central-1.amazonaws.com[52.28.191.33]:587, delay=0.45, delays=0.03\/0.06\/0.13\/0.23, dsn=2.0.0, status=sent (250 Ok 01070185de4b762a-1c453360-ba6f-49f2-bc7e-508941e8cc7e-000000)\nJan 23 12:02:45 srv-ol8-ora postfix\/qmgr[57485]: 46AC1140C215: removed\n<\/pre>\n<\/br>\n\n\n\n<p>As we can see in the log file, the email sending is now clean. I could confirm this as well getting the email in my email inbox. I could test and validate the same from the DMK software as well.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>For some internal DMK (https:\/\/www.dbi-services.com\/fr\/produits\/dmk-management-kit\/) development I had to configure a SMTP relay on my VM. Purpose of the SMTP relay is to send the email locally from DMK without any authentication. This Email will be transferred to the SMTP server created by one of my colleague on our AWS Cloud. This SMTP server is [&hellip;]<\/p>\n","protected":false},"author":48,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[59],"tags":[73,96,2817],"type_dbi":[],"class_list":["post-21914","post","type-post","status-publish","format-standard","hentry","category-oracle","tag-linux","tag-oracle","tag-smtp-relay"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v27.2 (Yoast SEO v27.5) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Configuring a SMTP relay on Oracle Linux Server v8 - dbi Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Configuring a SMTP relay on Oracle Linux Server v8\" \/>\n<meta property=\"og:description\" content=\"For some internal DMK (https:\/\/www.dbi-services.com\/fr\/produits\/dmk-management-kit\/) development I had to configure a SMTP relay on my VM. Purpose of the SMTP relay is to send the email locally from DMK without any authentication. This Email will be transferred to the SMTP server created by one of my colleague on our AWS Cloud. This SMTP server is [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/\" \/>\n<meta property=\"og:site_name\" content=\"dbi Blog\" \/>\n<meta property=\"article:published_time\" content=\"2023-01-23T14:00:01+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-01-24T12:07:36+00:00\" \/>\n<meta name=\"author\" content=\"Marc Wagner\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Marc Wagner\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/\"},\"author\":{\"name\":\"Marc Wagner\",\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/#\\\/schema\\\/person\\\/225d9884b8467ead9a872823acb14628\"},\"headline\":\"Configuring a SMTP relay on Oracle Linux Server v8\",\"datePublished\":\"2023-01-23T14:00:01+00:00\",\"dateModified\":\"2023-01-24T12:07:36+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/\"},\"wordCount\":540,\"commentCount\":1,\"keywords\":[\"Linux\",\"Oracle\",\"SMTP relay\"],\"articleSection\":[\"Oracle\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/\",\"url\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/\",\"name\":\"Configuring a SMTP relay on Oracle Linux Server v8 - dbi Blog\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/#website\"},\"datePublished\":\"2023-01-23T14:00:01+00:00\",\"dateModified\":\"2023-01-24T12:07:36+00:00\",\"author\":{\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/#\\\/schema\\\/person\\\/225d9884b8467ead9a872823acb14628\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/configuring-a-smtp-relay-on-oracle-linux-server-v8\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Accueil\",\"item\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Configuring a SMTP relay on Oracle Linux Server v8\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/\",\"name\":\"dbi Blog\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/#\\\/schema\\\/person\\\/225d9884b8467ead9a872823acb14628\",\"name\":\"Marc Wagner\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/a873cc6e7fbdbbcbdbcaf5dbded14ad9a77b2ec2c3e03b4d724ed33d35d5f328?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/a873cc6e7fbdbbcbdbcaf5dbded14ad9a77b2ec2c3e03b4d724ed33d35d5f328?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/a873cc6e7fbdbbcbdbcaf5dbded14ad9a77b2ec2c3e03b4d724ed33d35d5f328?s=96&d=mm&r=g\",\"caption\":\"Marc Wagner\"},\"url\":\"https:\\\/\\\/www.dbi-services.com\\\/blog\\\/author\\\/marc-wagner\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Configuring a SMTP relay on Oracle Linux Server v8 - dbi Blog","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/","og_locale":"en_US","og_type":"article","og_title":"Configuring a SMTP relay on Oracle Linux Server v8","og_description":"For some internal DMK (https:\/\/www.dbi-services.com\/fr\/produits\/dmk-management-kit\/) development I had to configure a SMTP relay on my VM. Purpose of the SMTP relay is to send the email locally from DMK without any authentication. This Email will be transferred to the SMTP server created by one of my colleague on our AWS Cloud. This SMTP server is [&hellip;]","og_url":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/","og_site_name":"dbi Blog","article_published_time":"2023-01-23T14:00:01+00:00","article_modified_time":"2023-01-24T12:07:36+00:00","author":"Marc Wagner","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Marc Wagner","Est. reading time":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/#article","isPartOf":{"@id":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/"},"author":{"name":"Marc Wagner","@id":"https:\/\/www.dbi-services.com\/blog\/#\/schema\/person\/225d9884b8467ead9a872823acb14628"},"headline":"Configuring a SMTP relay on Oracle Linux Server v8","datePublished":"2023-01-23T14:00:01+00:00","dateModified":"2023-01-24T12:07:36+00:00","mainEntityOfPage":{"@id":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/"},"wordCount":540,"commentCount":1,"keywords":["Linux","Oracle","SMTP relay"],"articleSection":["Oracle"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/","url":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/","name":"Configuring a SMTP relay on Oracle Linux Server v8 - dbi Blog","isPartOf":{"@id":"https:\/\/www.dbi-services.com\/blog\/#website"},"datePublished":"2023-01-23T14:00:01+00:00","dateModified":"2023-01-24T12:07:36+00:00","author":{"@id":"https:\/\/www.dbi-services.com\/blog\/#\/schema\/person\/225d9884b8467ead9a872823acb14628"},"breadcrumb":{"@id":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.dbi-services.com\/blog\/configuring-a-smtp-relay-on-oracle-linux-server-v8\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Accueil","item":"https:\/\/www.dbi-services.com\/blog\/"},{"@type":"ListItem","position":2,"name":"Configuring a SMTP relay on Oracle Linux Server v8"}]},{"@type":"WebSite","@id":"https:\/\/www.dbi-services.com\/blog\/#website","url":"https:\/\/www.dbi-services.com\/blog\/","name":"dbi Blog","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.dbi-services.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.dbi-services.com\/blog\/#\/schema\/person\/225d9884b8467ead9a872823acb14628","name":"Marc Wagner","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/a873cc6e7fbdbbcbdbcaf5dbded14ad9a77b2ec2c3e03b4d724ed33d35d5f328?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/a873cc6e7fbdbbcbdbcaf5dbded14ad9a77b2ec2c3e03b4d724ed33d35d5f328?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/a873cc6e7fbdbbcbdbcaf5dbded14ad9a77b2ec2c3e03b4d724ed33d35d5f328?s=96&d=mm&r=g","caption":"Marc Wagner"},"url":"https:\/\/www.dbi-services.com\/blog\/author\/marc-wagner\/"}]}},"_links":{"self":[{"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/posts\/21914","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/users\/48"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/comments?post=21914"}],"version-history":[{"count":6,"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/posts\/21914\/revisions"}],"predecessor-version":[{"id":21974,"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/posts\/21914\/revisions\/21974"}],"wp:attachment":[{"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/media?parent=21914"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/categories?post=21914"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/tags?post=21914"},{"taxonomy":"type","embeddable":true,"href":"https:\/\/www.dbi-services.com\/blog\/wp-json\/wp\/v2\/type_dbi?post=21914"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}