Fun new policy at AOL

Sometime mid last week, one of my clients--a state chapter of
a national
association--became unable to send to all of their AOL
members. Assuming
it was simply that AOLs servers were inundated with infected emails, I
gave it some time. The errors were simply "delay" and "not
delivered in
time specified" errors.

AOL appear to have recently changed their MX receiving policies, see the
following demon.announce post:

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One such scheme uses a list of "end user" IP addresses on the basis that
such users will only be sending legitimate email via their own ISP's
"smarthost" email server. The idea is that the blocklist will be able to
block non-legitimate email because it arrives directly. In particular it
should block "spam" sent via insecure systems or virus/worm infections.

We have recently been in discussion with AOL who are, at a future
date, planning to implement just such a scheme as they have found,
working with many ISPs around the world, that it significantly impacts
their incoming spam volumes.
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