[Mailman-Users] Problem with mailman and outlook.com

[Mark Sapiro]

On 10/09/2013 12:45 AM, Tim Sterk wrote:
> 
> They are moved into the unwanted box, so I was able to view the message
> and headers from there.


So they were not rejected but rather marked as spam and put in a spam
box rather than the inbox. Had they been rejected, you wouldn't have
seen them at all, and they would have been recorded as a bounce by Mailman.


> The interesting part for me is that this problem only applies to mail
> sent through mailman, if I'm sending an email to the same address from
> the same domain name it is accepted without a problem, so I'm thinking
> that there is something in the headers that triggers this reaction at
> outlook.com.


Exactly. It could be the 'Precedence: list' header or some other header
or combination of headers, but only Microsoft knows for sure, and they
won't tell you because they consider it proprietary information which
would be useful to spammers.

Since you apparently use Mutt and have your own server, you could
experiment by resending the message directly with all Mailman's added
headers and delete headers one by one to find the header(s) that trigger
it, but it is possible that this is a more complex situation than that
which depends on the presence of certain headers in combination together
with body contents.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan