Recent Posts

Is this email address disposable?

steve
Jun 8, 2023

Industry

As a consumer there are several different sorts of email address that are described as “disposable” or “temporary”.

What is a Cookie?

I’m not talking about biscuits, nor about web cookies, at least not exactly.

Unresolvable RFC.5321 domain at Yahoo

steve
May 30, 2023

Delivery Improvement , Technical

Seen this recently?

451 Message temporarily deferred due to unresolvable RFC.5321 from domain; see https://postmaster.yahooinc.com/error-codes

Is .edu a canary?

steve
May 26, 2023

Technical

Several times recently I’ve heard about something unusual happening email delivery-wise at academic domains that was new, and wasn’t being seen at non-academic domains on the same lists.

Want a link on WttW?

laura
May 9, 2023

Best Practices

There is an ever increasing amount of spam I am getting from various companies asking for links here on WttW.

These last few years have been something, huh? Something had to give and, in my case, that something was blogging. There were a number of reasons I stopped writing here, many of them personal, some of them more global. I will admit, I was (and still am a little) burned out as it seemed I was saying and writing the same things I’d been saying and writing for more than a decade. Taking time off has helped a little bit, as much to focus on what I really want to talk about.

“Friendly From” addresses

steve
May 1, 2023

Delivery Improvement , Technical

When we’re looking at the technical details of email addresses there are two quite different contexts we talk about.

Don’t break the (RFC) rules

steve
Apr 28, 2023

Delivery Improvement , Technical

It looks like Microsoft are getting pickier about email address syntax, rejecting mail that uses illegal address formats. That might be what’s causing that “550 5.6.0 CAT.InvalidContent.Exception: DataSourceOperationException, proxyAddress: prefix not supported – ; cannot handle content of message” rejection.

Life of an Email

steve
Oct 19, 2022

Delivery Improvement , Technical

I’m repeating the presentation I gave at M3AAWG in London for the Certified Senders Alliance.

It’s all about how to send an email by hand, and how knowing the mechanics of how an email is sent can help us diagnose email delivery issues.

We’re starting in about five hours from when I post this.

Register at https://register.gotowebinar.com/register/2268789893122531343