A number of senders are reporting that they’re getting unusual responses from AOL servers. The responses include:
421 mtain-dk10.r1000.mx.aol.com Service unavailable – try again later
554 mtain-dk03.r1000.mx.aol.com ESMTP not accepting connections
mtain-dk* are assigned reserved IP addresses. It looks like something broke inside AOL again, and lots of places are having trouble delivering mail there.
Per Boing Boing: the AOL postmaster page was hacked over the weekend.
As of now the site is restored. But I’m hearing that all the scripts are still down. This means no one can open tickets, sign up for FBLs, apply for whitelisting or check the status of reports. I expect this will be fixed soon, but for now it looks like AOL issues are going to be impossible to resolve.
AOL is currently returning “451 4.3.0 <invaliduser@aol.com>: Temporary lookup failure” in some cases when they really mean “550 user unknown.” This message from AOL should be treated as 5xx failure and the message should not be retried (if at all possible) and the failure should be counted as a hard bounce for list management purposes.
This is something broken at AOL’s end, and the guys with the magic fingers that keep the system running are working to fix it. Right now there doesn’t seem to be an ETA on a fix, though.
Even if you are a sender who is able to stop the retries, you may see some congestion and delays when sending to AOL for the time being. Senders who don’t get the message, or who are unable to stop their MTAs from retrying 4xx mail will continue to attempt delivery of these messages until their servers time out. This may cause congestion for everyone and a noticeable slowdown on the AOL MTAs.
AOL blog post on the issue
HT: Annalivia
Some news stories and links today.
Spamhaus has announced their new domain block list (DBL). The DBL is a list of domains that have been found in spam.