Hi RobiBue,
Thanks for the suggestion.
Full disclosure, I'm not really clear on what the Mailhost configuration does. The help blurb said is it's to "Minimize self-reporting accidents by identifying your e-mail host(s) to the Parser."
In any case, per your suggestion, I examined the header from the SpamCop messages and did, indeed, find a match. In the capture below, the second "Received: from" block says "by mx277.antispamcloud.com" which was in the list. I selected it.
However, I looked at the headers from all emails I've received from SpamCop thus far and the second "Received: from" is different on every one. But, the first "Received: from" block is the same on every one. Granted, the sampling is pretty small (five emails thus far). While "out8.antispamcloud.com" is NOT among the items in the Host/Domains: dropdown, the IP address IS among those in "Relaying IPsv4:" so I selected it.
Again, I really don't know what I'm doing but, a little more documentation from SpamCop would certainly be helpful.
JCC
************************************
Return-Path: <noreply@forum.spamcop.net>
Received: from out8.antispamcloud.com (out8.antispamcloud.com [46.165.223.16]) by SM14.internetmailserver.net with SMTP
(version=TLS\Tls12
cipher=Aes256 bits=256);
Sun, 5 Nov 2023 12:15:13 -0800
Received: from ec2-3-89-228-223.compute-1.amazonaws.com ([3.89.228.223] helo=ip-172-31-12-230.ec2.internal)
by mx277.antispamcloud.com with esmtp (Exim 4.92)
(envelope-from <noreply@forum.spamcop.net>)
id 1qzjWT-00ClR1-9O
for ****; Sun, 05 Nov 2023 21:15:10 +0100
Received: from localhost (localhost [127.0.0.1])
by ip-172-31-12-230.ec2.internal (Postfix) with ESMTP id DF7709ACC42
for <****>; Sun, 5 Nov 2023 19:55:36 +0000 (UTC)