BLOG

Tag: bounces

Changes coming to Verizon email

Last year Verizon bought AOL. As part of that merger some @verizon.net email is being migrated to the

No Comments

Asynchronous Bounces

There are three ways that an email can fail to be delivered: immediate rejection timeout asynchronous bounce Rejection A rejection is any delivery attempt where the sending smarthost can tell immediately that the mail can’t be delivered. That will often be when the receiving machine accepts a connection but returns a “hard bounce” or “5xx” […]

4 Comments

Yahoo DMARC articles worth reading

There are a bunch of them and they’re all worth reading. I have more to say about DMARC, both in terms of advice for senders and list managers affected by this, and in terms of the broader implications of this policy decision. But those articles are going to take me a little longer to write. […]

1 Comment

Example bounces due to Yahoo p=reject

There are a number of different bounces that people are reporting due to Yahoo publishing a DMARC record of p=reject. I decided to put some of those bounces here so confused users could find out what they needed to do. Comcast smtp;550 5.2.0 meQj1n01053u42A0HeQj3v Message rejected due to DMARC. Please see http://postmaster.comcast.net/smtp-error-codes.php#DM000001 Google smtp;550 5.7.1 […]

9 Comments

Increase in bounces at Y!

I’ve been seeing reports over the last few days about an increase in bounces at Yahoo. Reliable people are telling me they’re seeing some increase in “invalid user” bounces. You may remember Yahoo announced an overhaul of their mail product back in December. Reliable sources tell me that this is more than just interface revamp. […]

2 Comments

Thoughts on bounce handling

This week’s Wednesday question comes from D. What are your thoughts on bounce handling There’s no specific standard for bounce handling as we often talk about it. While a lot of people will mention the RFCs, the RFCs only say what to do with a single email that gets a 4xy or a 5xy during […]

1 Comment

Mail problems at AOL

Over the last few months there have been ongoing mail problems at AOL. These problems are all over the map and are resulting in a lot of delayed and unsent email. People are reporting a number of different error messages from AOL mail servers. These messages don’t seem to always be accurate or correct. A […]

45 Comments

Broken record…

The Return Path In the Know blog listed 4 reasons mailing those old addresses is a bad idea. Ashley, the author, is completely right and I endorse everything she said. (Although I’d really like to hear what happened to the customer that added back all those addresses. What was the effect on that campaign and […]

8 Comments

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 […]

6 Comments

Bounces, complaints and metrics

In the email delivery space there are a lot of numbers we talk about including bounce rates, complaint rates, acceptance rates and inbox delivery rates. These are all good numbers to tell us about a particular campaign or mailing list. Usually these metrics all track together. Low bounce rates and low complaint rates correlate with […]

1 Comment
  • HE.net DNS problems

    Hurricane Electric had a significant outage of their authoritative DNS servers this morning, causing them to return valid responses with no results for all(?) queries. This will have caused delivery problems for any mail going to domains using HE.net DNS - which will include some of their colocation customers, as well as users of their free services - but also will have caused reverse DNS to fail for most servers hosted by Hurricane Electric worldwide, so if any of your mail is being sent from HE hosted machines you may have seen problems. (We're HE customers so we noticed. Still happy with them as a vendor.)No Comments


  • 65.0.0.0/8 DNS issues

    If you're sending email from any address beginning with a 65 - in 65.0.0.0/8 - it's possible you'll see some delivery problems. Something appears to be broken with dnssec signatures for the reverse DNS zone, leading queries for reverse DNS to fail for anyone using a dnssec aware DNS resolver (which is almost everyone).1 Comment


  • Our green bar certificate is going away

    Later today we'll be switching from an Extended Validation ("green bar") SSL certificate to a Domain Validation certificate. This isn't exactly a planned change but I'm waiting for responses from Comodo before I go into it too much. I'll share some more details next week.3 Comments


Archives