Spam Resource: All Things Deliverability

Here's a question that I was asked recently: Where, exactly, does a BIMI email sender logo show in the inbox (or next to the inbox) in all the different email clients and web…

On the surface, email is magic. It just works. Messages go out, inboxes fill up, marketing and newsletters hum along. Underneath that smooth glide is a lot of frantic paddling, a…

Tom Mairs is co-founder of Kumo Corp . If you're not familiar, they're " Building the first Open-Source MTA made especially for large-volume senders. " Tom'…

Are you seeing this error message when trying to send emails to Gmail? 550-5.7.25 The IP address sending this message does not have a PTR record setup, or the corresponding forwa…

As this year rolls its way toward the exit, it is time for my annual roundup of the most popular blog posts published in the year 2025. A lot happened this year, in the world of …

Webinar alert! You've survived Black Friday and Cyber Monday, perhaps Giving Tuesday, too, maybe it ended up stretching into Cyber Week, or maybe it's still Cyber Month f…

It is time to clarify another common technology term here on Spam Resource. Today we're decoding 2FA , short for two factor authentication . You'll also see people use th…

Microsoft is removing support for inline SVG images in Outlook for Web and Outlook for Windows. This started rolling out in early September and should hit everyone by mid October…

How many people are still using Post Office Protocol (POP, aka POP3) to retrieve their email messages nowadays? And how many people were using POP to pull mail from an external …

The other day I found myself watching "Down Cemetery Road," a show on Apple TV based on a Mick Herron novel (yeah, the Slow Horses guy -- and the jury's still out o…

If you spend any time on social media, you undoubtedly saw the dire warnings. It was all over Reddit , and there were a wealth of news articles and hot takes posted. Folks were i…

I just found something very interesting, when poking around in DNS: Google seems to have recently updated what goes into their " _spf.google.com " SPF record. Keep in …

I'm sure you've heard the opinions already: Open rate tracking is absolutely useless. Open rates are a garbage metric. Open triggers attract only bots talking to other bo…

The Messaging, Malware and Mobile Anti-Abuse Working Group (M3AAWG) is an industry group focused on keeping messaging ecosystems safe from threats like email spam, phishing, spo…

For a recent Valimail Ask Al video , I brought in Scott Ziegler , Valimail's VP of product, to share some real world results showing the actual benefits seen by a Valimail cl…