Deploying a new smarthost using Postfix and other open source components. And why you probably shouldn't do that ..read more

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. (The SEO slop tends to do things like sign up for free accounts at a bunch of ESPs, send three emails to probe accounts and see how many ..read more

Adding your domain to the public suffix list might break all your email ..read more

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: My ESP provides a dashboard of spam complaints. How should I be looking at the data? Are some complaints more important than others? The spam complaint dashboard ..read more

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. When you’re diagnosing and mitigating hard bounce rates the first thing you’ll see is your ESPs dashboard or reporting. It’ll tell you how many emails you sent bounced, and how ..read more

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 ..read more

You should probably stop using Encert for BIMI certificates. Apple definitely think you should ..read more

How long does a tracking link need to be? Let’s make it interesting, and say we want to be able to have a unique tracking link for every single atom in the observable universe. That’s about 1080 unique links. One hundred novemdecillion exa-links. 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 If we have that many customers we can afford to buy ..read more

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. text/plain This is the simplest sort of text you can send. If you send ..read more

When a mailbox provider rejects or defers an email it sends back a message explaining why. Those messages begin with a three digit number (starting with a “5” for rejections and a “4” for deferrals), followed by text that explains why the mail wasn’t accepted. That text often contains a link to follow for more ..read more