I've been looking through Google Search results for a while, but I couldn't find any appropriate method for my system. So anyway, what I wanted to do was to append sender name to all sent mails from my system. At the moment, I've been using the generic file of postfix to change the Form header of mails from email@example.com to firstname.lastname@example.org, but I can't figure out how to append sender name. Currently, all sent mails (excluding the ones from XenForo and custom mail command) will be like this: But, what I want is this: I did that one with custom mail command, so I manually added a custom Form header. But for automated messages from yum-cron, etc., I don't know whether it's possible to change the Form header through postfix configuration instead.