Recent Posts

They Must Have Changed Something…

One of the most common refrains I hear from folks with delivery problems is that the filters must have changed because their mail suddenly started to go to the bulk folder. A few years ago, I posted about how even when there is no change in the sender’s behavior, reputation can slowly erode until mail suddenly goes to the Gmail bulk folder. Much of that still applies – although the comments on pixel loads (what other folks call ‘open rates’) are a bit outdated due to changes in Gmail behavior.

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Is this email address disposable?

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

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C is for Cookie

Trekkie Monster. He’s obsessed by social media and isn’t owned by Children’s Television Workshop.

What is a Cookie?

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

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Unresolvable RFC.5321 domain at Yahoo

Seen this recently?

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

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Is .edu a canary?

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.

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Want a link on WttW?

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

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Is email dead?

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.

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“Friendly From” addresses

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

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Don’t break the (RFC) rules

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.

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Life of an Email

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

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