AOL blocking DynDNS Mailhop-Outbound

[Robert Krawitz]

On Mon, 08 Nov 2010 21:46:29 -0400, Tom Metro wrote:
> Rich Braun wrote:
>> Tom Metro asked:
>>> ...the vast majority of ISPs have customers using dynamic IP
>>> ranges connecting to a mail relay. These dynamic IP addresses almost
>>> always appear in some of the headers.
>> > ...probably fewer than 1% of ISP customers fit into your description:
>> most of us punt on having our mail servers and just use the ISP's
>> webmail service.
>
> I agree that those who run their own servers make up a tiny minority,
> but I would guess there is still a significant percentage that relay
> mail through their ISP from a desktop client. Webmail may be popular,
> but aren't major ISPs, like Comcast, still distributing software bundles
> that configure a user's desktop to connect to their servers using
> Outlook Express or some other desktop MUA?
>
> Messages relayed from desktop users should have essentially the same
> traces of dynamic IPs embedded in the headers.

Perhaps, but it's possible that passage through a downstream trusted
MTA "sanitizes" them (i. e. that AOL trusts Comcast's servers if it
comes from them).