BLOG

Category: FAQ

Identifying domains that don’t accept or send email

A couple folks have asked me recently about MX records that they don’t understand. These records consist of a single . or they contain localhost or they are 127.0.0.1. In all cases, the domain owners use these records to signal that the domains don’t accept email. What do these records look like? Why do domains […]

1 Comment

Null sender address

A question came up on the email geeks slack channel about empty from addresses. I asked if they meant the 5321 or 5322 from address which prompted a question about if you could even have a null 5321 from. Yes, you can and it’s commonly used for some types of email. 5321.from is the bounce […]

No Comments

Spamtraps are overblown… by senders

One of the fascinating parts of my job is seeing how different groups in email have radically disparate points of view. A current example is how much value senders put on spamtraps compared to ISPs and filtering companies. I understand why this is. In all too many cases, when a sender asks why they’re mail […]

3 Comments

SenderID is dead

A question came up on the email geeks slack channel (Join Here) about SenderID. They recently had a customer ask for SenderID authentication. We’ve written about it a few times: (Hotmail moves to SPF Authentication and Until it stops moving) but we’ve not actually stated the reasons why in a post. SenderID was basically SPF […]

5 Comments

Deliverability Help: Information checklist

When asking a for assistance with email delivery, there are some pieces of information that are required before anyone can help. Be prepared with the information so you can get timely assistance. This advice is true whether you’re looking for help from peers or working with paid deliverability consultants. What is the problem? Be very […]

No Comments

What SPF records should you publish?

When it comes to SPF records there seems to be a lot of confusion. I mean, a decade after I posted it Authenticating SPF is still the most frequently visited post on the site. And, of course, there are hundreds of other pages out there that discuss SPF and what to publish. Still, there are […]

3 Comments

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. […]

No Comments

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 […]

8 Comments