I'm using a pre-configured virtual server for sending emails. Currently, I'm responsible for it running well. One recipient refused my email and I was pointed to a page explaining it. But to me it explains nothing at all:
abcde1234 rejected a message that claimed an envelope sender address of email@example.com. abcde1234 received a message from 184.108.40.206 that claimed an envelope sender address of firstname.lastname@example.org. However, the domain cgc-instruments.com has declared using SPF that it does not send mail through 220.127.116.11. That is why the message was rejected.
In the above I replaced
18.104.22.168 for the real values.
So my server has declared... maybe it has, how do I find it out without knowing anything about the system? By running
ps I've learned that there's
qmail running. Why are there no config files in
/etc? I've found them in
/var/qmail/control, but there's nothing like the above there. Or is it?