DKIM is an email authentication method that uses a digital signature to let the receiver of an email know that the message was sent and authorized by the owner of a domain. To enable DKIM on your domain with Zimbra you will need to use the zmdkimkeyutil utility You can…
I recently experienced an issue when I was connected to the Zimbra admin portal, in that the Server Status stats were not updating. When I ran a zmcontrol status all of the services where showing as running. To resolve this I restarted the logging service: The stats run every two…
This post will walk you through setting up DKIM with Postfix on your Ubuntu 18.04, 20.04 or 22.04 Server. Setting up DKIM First, install OpenDKIM which is an open-source implementation of the DKIM sender authentication system. Then add postfix user to opendkim group. Edit OpenDKIM main configuration file. Uncomment the following lines. Replace simple with relaxed/simple. Then…
I recently came across an issue on an Ubuntu 20.04 installation recently when I setup Postfix using a smart relay with authentication. But when mails were sent, the following error was being recorded: I did some research and found I needed to install the libsas12-modules. I though I would share…
If you ever find that you need to send out email from your server via a relay, as you cannot send them out directly from your server’s IP (eg its been black listed). Relaying the mail via Mailgun is a good option. To do this you will need to setup…
Address rewriting allows changing outgoing email ID or domain name itself. This is good for hiding internal user names. For example:SMTP user: user-01EMAIL ID: [email protected] name: server.domain.com However when user-01 send an email from shell prompt or using php it looks like it was send from [email protected] Postfix MTA offers smtp_generic_maps parameter….
Below are a list of useful commands for managing a postfix mail server: mailq – Use to list items in your mails queues postcat -q MESSAGE_ID – Used to read messages that are in your postfix queue postsuper -d ALL – Delete all queued messages postsuper -d ALL deferred – Delete all messages in…