Trying to understand some email issues

[Patrick Mahan]

All,

FreeBSD 11.2

Running postfix 3.3.2_1,1

I'm getting hammered with thousands of emails from yahoo.com -

Here is an example -

Jan 20 22:09:01 ns postfix/smtp[1308]: 2DA97A2E2EF: to=<pwascak at aol.com>,
relay=mx-aol.mail.gm0.yahoodns.net[98.137.157.43]:25, delay=13730,
delays=13728/0.31/1.1/0.06, dsn=4.7.0, status=deferred (host
mx-aol.mail.gm0.yahoodns.net[98.137.157.43] said: 421 4.7.0 [TSS04]
Messages from 23.24.207.145 temporarily deferred due to user complaints -
4.16.55.1; see https://help.yahoo.com/kb/postmaster/SLN3434.html (in reply
to MAIL FROM command))

I'm trying to determine if I am somehow relaying emails to yahoo.com, or is
this someone attacking me.

I am pretty sure I have postfix to avoid acting like a relay for
unauthenticated connections.  But this maybe something I have messed up.
This has been happening only since I upgraded to 11.2 (I was at 9.x).  I
also just recently switch from sendmail to postfix as well.

I can provide my postfix config on request if needed.

Pointers to other mail-lists are welcomed.  I decided to start here before
jumping on the postfix mailing list.

Thanks in advance,

Patrick