AOL Updates Spam Filtering

Over on the AOL Postmaster blog, Lili Crowley announced yesterday that AOL has made changes to their spam filtering system. Specifically, more senders may be subject to blocking with CON:B1 errors. AOL’s website explains that CON:B1 errors indicate that an IP address is being  blocked “due to a spike in unfavorable e-mail statistics.” This strongly suggests that a sender blocked with a CON:B1 error message has a negative sending reputation. This is yet another data point as to how ISPs have been tightening up spam filtering and reputation requirements over the past few years. What you might have been able to deliver five years ago, you might not be able to get delivered today.

Related Posts

AOL Postmaster page hacked

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.

Read More

Mail problems at AOL

We cannot help endusers troubleshoot AOL connection problems. Please do not call. Please do not write. You need to talk to AOL. We are not AOL. We cannot help you. 

Read More

AOL bounces and false positives

A number of people have been seeing an increase in AOL bounces over the last few days. Some of these are the new rejection 554/421 CON:B1 message. This is, basically, you’ve topped our thresholds, back off.
The other one is a bit more interesting. The error message a lot of people are seeing is 554/421 RLY:SN. Senders should only be getting this error message when they are sending email from a banned address.

Read More