[Mailman-Users] Mailman Hosting

[Richard Shetron]

Maybe they were using some type of grey listing.

For those who don't know:
Grey listing is where the target MTA rejects with a retry error code the 
email from a new source for some period of time.  Every site can set 
their own delay.  Most spammers won't retry so it gets rid of a lot of 
spam.  Real email servers will accept the retry error (4xx) and retry 
after some prefigured time from a few seconds to an hour or more.  The 
IP addresses are tracked and if retried after the time limit are white 
listed for anywhere from a few hours to a month or more.

On 12/23/2016 1:40 AM, Mark Dale wrote:
> Thanks for the suggestion on the mailop list Jim.
>
> Verizon began accepting mail again for lists on the European server
> about 6 hours ago.
>
> No light was shed as to why or what changed their view. Not only Verizon
> but AT&T as well, at around the same time - a little puzzle that's
> probably best left alone.
>
> It may be that their default position is to block all list mail
> regardless - until they get swamped with complaints.
>
> I've subscribed to the mailop list as you suggest, and if I learn
> anything relevant to this issue I'll post it back here.
>
> Thanks,
> Mark
>
>
>
> ========================================
>  MailmanLists - hosted discussion lists
>  Canberra, Australia
>  Tel: +61 .2 61003121
>  http://www.mailmanlists.net
> =======================================
>
> On 22/12/16 16:15, Jim Popovitch wrote:
>> On Wed, Dec 21, 2016 at 11:42 PM, Mark Dale <mark at mailmanlists.net>
>> wrote:
> ...
>>> All the DNS records (inc SPF, DKIM) are in place, the server is on no
>>> RBLs,
>>> con-current connections to the recieving mail servers is set at 2 in
>>> Postfix. In short, all the right boxes are ticked as far as we can see.
>>>
>>> Point noted about the time needed to build a good IP reputation. In
>>> light of
>>> that, we moved the list to our old established server in Europe. It
>>> has a
>>> SenderScore of 99, and of course all the same boxes are ticked. Verizon
>>> still rejected list mail.
> ...
>>>
>>
>> A good place to start is on the mailop list, explain your company and
>> sign-up practices/filtering, etc.  Be open and ask for specific reps
>> to contact you offline if necessary.  You may get some awesome help,
>> although this close to the holidays your message may not hit the right
>> people until next year.
>>
>> https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
>
> ------------------------------------------------------
> Mailman-Users mailing list Mailman-Users at python.org
> https://mail.python.org/mailman/listinfo/mailman-users
> Mailman FAQ: http://wiki.list.org/x/AgA3
> Security Policy: http://wiki.list.org/x/QIA9
> Searchable Archives:
> http://www.mail-archive.com/mailman-users%40python.org/
> Unsubscribe:
> https://mail.python.org/mailman/options/mailman-users/guest2%40sgeinc.com
>