I’ve shared a version of this image repeatedly. I think it was only my Facebook friends that got the stick figure screaming in frustration, though. The reality is bounce handling is one of the most frustrating pieces of email delivery. Not only that, many people in the email space treat it as a simple process. It’s really not as simple as we’d like it to be. The above image was...
New Deliverability Resource
The nice folks over at Postmark shared a new deliverability resource last week. The SMTP Field Manual. This is a collection of SMTP responses they’ve seen in the wild. This is a useful resource. They’re also collecting responses from other senders, meaning we can crowdsource a useful resource for email deliverability folks.
Share your average bounce rates
The question came up on slack this morning about bounce rate benchmarks. What are the normal / average bounces that different ESPs see? Does region matter? What’s acceptable for bounce rates? Bounce rate is an overall measure of address quality Here’s your the chance for ESPs share the data from your customers. We’re interested in anything you care to share. But more detail is...
Undelivered mail without a bounce
A few weeks ago I wrote a blog post focusing on one small part of bounce handling. Today I want to talk about delivery failures that aren’t bounces. This is really the biggest issue for companies who have written their own bulk sending servers. Modern bulk MTA appliances and ESPs correctly handle these types of bounces. However, when you’re troubleshooting it’s important to know...
What’s a bounce?
Bounces and bounce handling is one of those topics I’ve avoided writing about for a long time. Part of my avoidance is because there are decades of confusing terminology that hasn’t ever been really defined. Untangling that terminology is the first step to being able to talk sensibly about what to do. Instead of writing a giant long post, I can break it into smaller, more focused...
Engagement drives deliverability
Return Path released an white paper today offering the Secrets of Successful Senders. I don’t think any of my readers will be surprised that it boils down to identity, reputation, and engagement. Return Path treats these as separate things and I understand why they do. I think however, that the identity and reputation are supporting players to the overarching issue of engagement. When...
March 2017: The Month in Email
It’s that time again… here’s a look at our last month of blog posts. We find it useful to recap each month, both to track trends and issues in email delivery and to provide a handy summary for those who aren’t following along breathlessly every single day. Let us know if you find it useful too! As always, I wrote about email filters. It’s so important to recognize that filters aren’t arbitrary...
AOL accidentally hard bounces valid mail
Last night (Mar 29, 2017) between about 8pm Eastern and 9:30pm Eastern AOL suffered a technical issue. Every email sent to them received a “Recipient address rejected” reply. One example of the error message: Mar 29 20:45:12 p2-lvmail11 lsb1-99-208-250/smtp[22251]: A88DFC2DBE9: to=<redacted@aol.com>, relay=mailin-01.mx.aol.com[64. 12.91.195]:25, delay=0.18, delays=0.01/0/0.14/0...
Relaying Denied
I’ve got multiple clients right now looking for insights about bounce handling. This means I’m doing a lot of thought work about bounces and what they mean and how they match up and how different ISPs manage delivery and how different ESPs manage delivery and how it all fits together. One thing I’ve been trying to do is contextualize bounces based on what the reason is. Despite...
Vague reports of Yahoo problems
A number of people, on different forums, have been asking if anyone is seeing a higher bounce rate than usual with Yahoo. Not sure exactly what’s going on here. As I understand it, folks are talking with Yahoo about it. If I hear anything more, I’ll share. For now, though, if you’re seeing a small increase in Yahoo bounces (or other weirdnesses) others are seeing something odd...