[Mailman-Users] msg marked as spam 554 5.7.1 [P4]

[Jim Dory]

So I'm just a volunteer who doesn't understand much about email systems..
just rudimentary - and I am managing an email list for community
announcements and trade, by subscription only. We have about 1500
subscribers.

I have one problem that when a particular user (the city) sends an
announcement, it tends to bounce hundreds of mainly one ISP's users.. that
ISP being Alaska's GCI.com . Other users, say on hotmail, yahoo, etc..
don't get bounced. I manage the emails via gmail and lately I've been
"locked out of gmail due to suspicious email activity" which is a pain in
the rear. Also causes my host (Hawkhost) grief.. the overhead they dislike
though they haven't complained lately. So I'm motivated to look into this a
bit.

Sometimes I do get this: host mx1.arandomserver.com [198.252.100.64]
    SMTP error from remote mail server after end of data:
    550 Headers contain illegal BOM
on my personal email from the same sender (city), but not sure that is same
issue.

The city usually includes a link to the city codes on a public webpage -
perhaps that triggers GCI.

I could post one of the headers in total but it is probably about 3 pages
worth. Everything sort of looks ok to me except I notice this:
BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0
RCVD_IN_DNSWL_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to DNSWL was
blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block
for more information. [34.212.96.103 listed in list.dnswl.org] -0.0
SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML
included in message

The link in the messages is https://www.codepublishing.com/AK/Nome/ .

I can post more of the header if need be.

Could it be that GCI needs to whitelist or something?

thx, Jim