[Mailman-Users] DMARC issues

[Jim Popovitch]

On Sat, Apr 12, 2014 at 8:17 PM, Peter Shute <pshute at nuw.org.au> wrote:
>> On 13 Apr 2014, at 8:20 am, "Jim Popovitch" <jimpop at gmail.com> wrote:
>>
>>> But note that the part of the threadable article I quoted talks about not *delivering* to yahoo addresses. I would thought that shouldn't be a problem.
>>
>> The recent yahoo change means that you (as a mailinglist operator)
>> will have difficulties (and possibly eventually face blacklisting) by
>> delivering, via your list, email that originates from a yahoo.com (and
>> a few other) email address.  Assuming you are doing SPF/DKIM/etc, you
>> should have no problems delivering non-yahoo domain emails to yahoo.
>
> I don't know if we are doing SPF/DKIM ( or what they are). It's just a cpanel implementation of mailman. Are you suggesting we *could* have problems if we deliver non yahoo emails to our yahoo subscribers too?

No.  You will be OK if you deliver non-yahoo email to yahoo (assuming
that yahoo accepts email from you).

You *may* get into long term trouble (blacklisting) *IF* you deliver
yahoo email to any other company/person that checks yahoo's DMARC
record.   Yahoo's recent change (DMARC p=reject) stipulates for
everyone else to outright reject yahoo email from anyone other than
yahoo.   This has the potential for others to report your mailinglist
as doing something malicious.

-Jim P.