[CentOS] Some subscribers posts to the list ending up in Gmail spam

Wed Apr 8 18:11:56 UTC 2015
Nataraj <incoming-centos at rjl.com>

On 04/08/2015 09:40 AM, Laurent Blume wrote:
> Le 2015/04/08 17:50 +0200, Les Mikesell a écrit: 
>> No, I don't think it will ever learn from that,, but there is a way
>> you can set a rule to 'never mark as spam' based on the sender. Which
>> wouldn't be fun on a list with a lot of yahoo.com members.
> FWIW, I recently solved one reason GMail was always marking my emails as
> spam: my MTA has IPv6, and to send emails, it was by default using the
> rfc3041 temporary addresses as source, so each time a different address
> when connecting to Google's MX's.
>
> As soon as I set it up to use the propre static IPv6, marking them as
> «not spam» in Gmail subsequently worked. So it looks like they also keep
> track of the sender's MTA address, not only of the email address.
>
> Obviously not the reason for everybody, but hopefully it can help others :-)
>
> Laurent
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> http://lists.centos.org/mailman/listinfo/centos

Gmail has many different criteria that it uses for detecting spam.  One
of the things they do is to keep a credibility score based on the IP
address of a mailserver.  In general, they like to see all of the mail
for a domain coming from a single IP address.   Since mail.centos.org
uses a single IP address, this is not the problem here.

If one wanted to improve this situation, my sense is that the next thing
to do would be to strip off the DKIM signatures which have incorrect
checksums.

After that, the next thing that would improve gmail's spam scoring of
list mail would be to add a valid DKIM signature, but that is messier
for a mailing list because it would mean ugly rewriting of the from
header.  It is possible that simply stripping the original senders
DKIM's would solve the problem.

Nataraj