On Sun, 2014-09-28 at 19:27 -0500, Les Mikesell wrote:
Applications often send mail by piping to the command 'sendmail' which is enough of a standard that other MTAs normally offer a compatible command. With 'real' sendmail you can configure it to either deliver in the current process or to queue for subsequent delivery by the daemon. Not sure how the others handle it, but yours apparently completes the delivery.
Sendmail is not present on the server. Exim is the only MTA. Exim awoke, forwarded the email then became inactive (not running) again.
I was curious how a non-running Exim can be run, solely to forward mail, then returned to its inactive state. I assume some system software identified the PHP outgoing email, and launched the only MTA installed (Exim) just to handle the outgoing email.