[Mailman-Users] List posts sent to AOL list subscribers bounce as undeliverable (v. 2.1.20)

[Natu]

On 12/04/2015 02:40 PM, John Levine wrote:
>> The issue is that list posts sent to AOL subscriber addresses are now bouncing as undeliverable with the bounce code: "521
>> 5.2.1 :  AOL will not accept delivery of this message."
> I see that you have a yahoo.com address.  If there's a yahoo.com
> address on the From: line of the list mail, AOL and Yahoo's well
> documented abuse of DMARC will cause the failure you're seeing.
>
> If you're running a recent version of Mailman, there are some DMARC
> workarounds you can use.  Other than that, I'd find a different
> address to mail from, not at Yahoo, not at AOL, and preferably not at
> Gmail.
>
> R's,
> John
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Two things to look at:

Enter the IP address of your server on the AOL IP reputation page.  I
don't know if it will give you anymore information than what you already
have, but it's probably worth a try:
https://postmaster.aol.com/ip-reputation

I don't believe you mention anywhere whether there are any kind of DKIM
signatures in your message or weather there is an SPF record for your
sending domain.  You could subscribe to your list from a gmail account,
and then, on one of the lists postings,  click "show original message"
(in the GMAIL GUI) and look for gmail's results of the DKIM, SPF, and
DMARC tests.  If you use from_is_list, or for digests, it is best to
have a valid DKIM signature.  If you don't use from_is_list, then no
signature is your best bet if mailman is adding footers.  My sense is
you stand the best chance of getting your message through if it has a
valid DKIM signature.  A bad DKIM signature will likely cause problems. 
I know that under some circumstances mailman strips dkim signatures, but
it's best to look at headers to see what is actually happening.

I realize you have no ability to change some of these things, but at
least determining the cause of your problem will help to determine if
you will be able to solve it or not.


Natu