[CentOS] Tracking down application sending mail in CentOS 7

Kenneth Porter
Thu, 24 Jun 2021 02:15:03 -0000

--On Wednesday, June 23, 2021 10:54 PM -0400 H <agents at meddatainc.com>
wrote:

> Viewing /var/log/maillog I get some information but cannot see which
> application generated that e-mail, nor the content of it which would
> likely allow me to see where it comes from.
>
> Can anyone suggest how to track down the app so I can reconfigure the
> mail address?

Hold all delivery so you can examine the mystery message in the queue. I
found this article on how to hold mail with Postfix:

<https://serverfault.com/questions/92981/how-do-i-temporarily-suspend-mail-delivery-to-a-specific-domain-non-local-with>

This requires creating the file /etc/postfix/hold with a static hold rule
and "compiling" it with the postmap command. Add a line to main.cf to
use
the new map.