Recent Posts

How to choose an ESP based on deliverability

Despite what a lot of SEO slop will try and tell you there’s no way to measure deliverability performance across multiple ESPs in any way that’s meaningful.

Read More

Don’t add your domain to the Public Suffix List

(At least, not if you ever intend to use it for email. It might break the domain for email, maybe forever.)

Read More

Are Complaints Weighted?

I’ve been doing a lot of my question answering over on the Email Geeks slack and have decided to bring some of the answers over here. Today’s question:

Read More

Diagnosing Hard Bounces

A very short post about diagnosing hard bounces, because I’ve had to give the same advice to a dozen folks over the past few months.

Read More

Effects of the Yahoo and Google Changes

In October 2023, Yahoo and Google announced new standards for sending bulk mail to their systems. For bulk senders these changes included requiring aligned authentication and publishing a DMARC record and complying with the List-Unsubscribe RFC. The ISPs also formally announced complaints must stay below a threshold of 0.3%. At the time of the announcement, they said enforcement would start in February 2024. As with many things, this enforcement deadline was pushed as ESPs explained the challenges to meet the deadlines.

Read More

Stop using Entrust for your BIMI Certificates

In July I talked about how Entrust was mistrusted by, well, pretty much everyone due to a years long series of security and trust violations.

Read More

Tracking link maths

galaxy

How long does a tracking link need to be?

Read More

There’s text and then there’s text

If you want to send someone an email with some text in it there are quite a few different ways you can do it. The main differences are the ways the text is packaged up in MIME entities to be sent.

Read More

Your bounce classification is a bit rubbish

When a mailbox provider rejects or defers an email it sends back a message explaining why.

Read More

Do we care about SPF alignment?

SPF and DKIM are the two main ways we associate a domain name with a stream of email in an authenticated way. We can choose the DKIM signing domain fairly freely – we can choose any domain or subdomain we control and put it in the d= field of the DKIM signature. But our choice for the SPF domain is more constrained.

Read More
Categories
Tags