History

Return Path was a major driver for the establishment of Feedback Loops (FBLs) back in the mid to late 2000s. They worked with a number of ISPs to help them set up FBLs and managed the signup and validation step for them. In return for providing this service to senders and receivers, they used this data as part of their certification process and their deliverability consulting. Return Path had a strong corporate ethos of improving the overall email ecosystem that originated from the CEO and permeated through the whole organization.

The trouble with CNAMEs

When you query DNS for something you ask your local DNS recursive resolver for all answers it has about a hostname of a certain type. If you’re going to a website your browser asks your resolver for all records for “google.com” of type “A”¹ and it will either return all the A records for google.com it has cached, or it will do the complex process of looking up the results from the authoritative servers, cache them for as long as the TTL field for the reply says it should, then return them to you.

Unsubscribe vs Suppress

When someone sends a complaint to your compliance desk there are a range of things you want to do, but one thing you always want to do is ensure that the recipient doesn’t receive any more unwanted email from your customer. Or, at least, not from your network.

How to Unsubscribe

Eventually our subscribers won’t want our email in their inbox any more.

The Case of the 500-mile Email

I stumbled across this story again this morning, and it’s such a lovely delivery yarn I thought I’d share it.

iOS17 filtering click tracking links

I’ve heard quite a bit of concern about what iOS 17’s automatic removal of click-tracking parameters means, but less discussion of what it actually does.

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 Much of that still applies – although the comments on pixel loads (what other folks call ‘open rates’) are a bit outdated due to changes in Gmail behavior.

Is this email address disposable?

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

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.

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

Recent Posts

Validity Charging for Feedback Loop Emails