AOL 421 errors

David Hubbard dhubbard at
Wed May 3 20:51:17 UTC 2006

From: owner-nanog at [mailto:owner-nanog at] On 
> We've noticed a surge in 421 e-mail errors from AOL.
> Message soft bounced for '', '4.3.2 - Not 
> accepting messages at 
> this time ('421', [': (DYN:T1) 
> AVAILABLE']) []'
> It seems as though they've tightened down their policies.
> We're pretty good at preventing spam with our IronPort
> anti-spam gateways and internal policies.
> We've also subscribed to their FBL notification service.
> I'm surprised at the types of messages AOL customers consider
> as spam. Anything and everything: university admission acceptance
> notices; instructor class assignments; photos from friends; etc.

AOL users report receipts for things they have bought or
letters from their kids as spam, or just use the spam button
instead of delete.  We have a feedback loop with them on a
netblock we moved off of about 24 months ago; I've emailed
their postmaster at least 12 times with no response and no
change.  I've called and they refuse to talk and say I must
email or use the form on the postmaster site to be removed;
no effect.


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