[Cialug] Postfix killed

[L. V. Lammert]

The postfix daemon died on a system last week, .. last journal entry:

Feb 21 06:18:06 core postfix/master[2252]: warning: process
/usr/lib/postfix/bin//qmgr pid 2255 killed by si> Feb 21 06:19:05 core
systemd[1]: postfix.service: Main process exited, code=killed,
status=9/KILL
Feb 21 06:19:05 core systemd[1]: postfix.service: Failed with result
'signal'

--

What scenario would cause main to be killed? Logs are normal emails
before.

	TIA!