I'm pulling together information from various sources here, and using a bit of guesswork. So keep in mind that this info is not guaranteed.
When sending mail to Charter/TWC/RoadRunner domains (full list here), are you seeing any of these bounces?
550 5.1.0 sender rejected AUP#I-1310
550 5.1.0 sender rejected AUP#I-1320
550 5.1.0 sender rejected AUP#I-1330
These apparently correlate to the ISP's Cloudmark servers putting a sender into a rate limited "time-out" for anywhere from five minutes up to 24 hours. According to a post on Mailop from 2017, one bounce means 5 minutes, another means a one hour timeout, and the third means a 24 hour timeout. They might be listed in that order above, but I'm not sure.
Anyway, the net here is: In addition to investigating the underlying potential reputation issue (don't be a spammer, please?), you might want to slow down sending if getting the first or second error message. Perhaps throttle sending to trickle out over a number of hours instead of allowing as much mail to send as possible at any given second.
Information on dealing with Charter/Roadrunner deliverability issues is sparse (they no longer have a Postmaster site, alas), so I thought it'd be good to share this (best guess) information here with the hope that other folks will find it useful.
I'm pulling together information from various sources here, and using a bit of guesswork. So keep in mind that this info is not guaranteed.
When sending mail to Charter/TWC/RoadRunner domains (full list here), are you seeing any of these bounces?
- 550 5.1.0 sender rejected AUP#I-1310
- 550 5.1.0 sender rejected AUP#I-1320
- 550 5.1.0 sender rejected AUP#I-1330
These apparently correlate to the ISP's Cloudmark servers putting a sender into a rate limited "time-out" for anywhere from five minutes up to 24 hours. According to a post on Mailop from 2017, one bounce means 5 minutes, another means a one hour timeout, and the third means a 24 hour timeout. They might be listed in that order above, but I'm not sure.Anyway, the net here is: In addition to investigating the underlying potential reputation issue (don't be a spammer, please?), you might want to slow down sending if getting the first or second error message. Perhaps throttle sending to trickle out over a number of hours instead of allowing as much mail to send as possible at any given second.
Information on dealing with Charter/Roadrunner deliverability issues is sparse (they no longer have a Postmaster site, alas), so I thought it'd be good to share this (best guess) information here with the hope that other folks will find it useful.
Comments
Post a Comment
Comments policy: Al is always right. Kidding, mostly. Be polite, please and thank you.