johannes.wolf--- via Mailman-users writes:
I am referring to the emails confirming the subscription or the approval notification to the list administrator. These emails are generated during the respective actions, but when I look at the log on my mail server, some of the emails only have a sender but no recipient.
Postfix is a multi-daemon system. Log messages like this:
Dec 01 14:05:01 turnbull.jp postfix/qmgr[731085]: C8CC22032D:
from=<steve@turnbull.sk.tsukuba.ac.jp>, size=4005, nrcpt=4
(queue active)are common for the 'qmgr' daemon. But the 'smtpd' daemon's messages usually has both "from=" and "to=" phrases. (This is just from a quick look at my own logs, not reliable except that I'm not surprised that some log messages had no explicit recipient.)
As Mark says, you should provide examples of the log messages you're describing.
Shouldn't the Postfix service on the Mailman server simply forward the email to the “external” mail server for sending?
That depends on what else it is doing. If there are ordinary users or certain daemons sending email offsite, there should be spam checking. In an enterprise setting, there might be checks for data exfiltration or insertion of legal disclaimers.
Steve
-- GNU Mailman consultant (installation, migration, customization) Sirius Open Source https://www.siriusopensource.com/ Software systems consulting in Europe, North America, and Japan