AOL + Cox Emails Bouncing?

[Dan_Askin]

Over the past week or so, we’ve seen a serious issue with hard bouncing addresses from AOL and Cox. These are aliases that ostensibly reached inboxes a week prior, too, according to the 'delivered' metric. Anything on anyone's radar? Investigating to the extent I can.

[Josh_Hill13]

Haven't heard much. You could check list counts and ask Kiersti Esparza​ if they know of anything.

If your sends are large to those ESPs, you may need to throttle somehow.

[Casey_Grimes]

There's been nothing about any specific outages in the email groups I'm a part of (not Marketo-specific.)

That said, if you're noticing certain ESPs are consistently bouncing, have you checked the messages returning with those bounces? That will probably give you a little more insight. I have a couple of hints at what might be happening with AOL, but I haven't dealt with high-volume B2C in a while, so Cox is a little less clear.

Feel free to drop me a line at courtney@demandlab.com if you'd like to dig a little deeper. Thanks!

[Dan_Askin]

Thanks, Josh and Courtney. Will try Kiersti.

The AOL error is some variation of:

554 mtaig-maa01.mx.aol.com ESMTP not accepting connections 421 4.7.0 mtaig-maa01.mx.aol.com Error: too many errors

[Casey_Grimes]

Hi Dan,

Unfortunately, the "Error: Too Many Errors" message is essentially saying whatever AOL initially sent back continues to apply. You'll need to dig the root cause from the earliest @aol emails sent when this started occurring.