Re: [exim] AOL onus when sender verify fails?

On 9/13/07 4:00 AM, "Simon Hobbs" <info@???> wrote:

> One of my users receives mail from an AOL listserver. The digest fails
> to reach him on every second day. To investigate the issue, I subscribed
> for a while via an unrelated mail server which doesn't do sender
> verification. The difference in the headers was fairly obvious:
>
> On bad days
> (envelope-sender
> <owner-THEATRE-SOUND?joesmith??EXAMPLE?-COM@???>)
>
> On good days
> (envelope-sender <owner-THEATRE-SOUND@???>
>
> Assuming I *should not* whitelist AOL, that I should put the onus
> squarely back on AOL, how should I word this message and who should I
> send it to? If I can understand the issue better, I can inform my user
> as to why the responsibility should rest with AOL.

G'day...

1. AOL isn't going to change.
2. It appears that AOL is using VERP-like processing on alternate days, to
help with bounce processing. That's fairly common (it saves
bandwidth--internet-wide--compared with VERPing on every list send).
3. Why wouldn't you whitelist the AOL servers (as distinct from @aol sender
addresses, of course), with respect to sender verification callouts? Do you
actually find AOL servers sending out messages from non-existent @aol.com
addresses?

4. It's not clear, however, why AOL would fail sender verification callouts
with their VERPed addresses. They do want those bounces (those are the more
useful ones to a mailing list system).

I see you having two choices, given item 1:
Change your server so that the AOL practice works, or tell your user to
subscribe using some other address (depending on your market, that could be
the same as telling the user to go away altogether).

This has been pretty much a guess, because of the "improvements" you made in
the information you sent us.

--John