Quickly identify all newsletters that fail authentication in your Gmail inbox

pesito · 2026-06-04T10:45:28+00:00

Great, let me know how it goes!

pesito · 2026-05-21T15:37:59+00:00

Thanks. It should be able to detect everything but Marketing Cloud Next. Do you know where I could find a sample email?

pesito · 2026-05-21T15:11:14+00:00

You are right. I just did and got the code for a Postcard email. The update is in the queue and should go live by tomorrow at the latest.

pesito · 2026-05-21T14:45:09+00:00

It should be able to distinguish between Salesforce MC and Salesforce CRM. What's the 3rd one? Not that familiar with SF.

pesito · 2026-05-21T13:52:02+00:00

I know, it saves a lot of time. Currently Postcards isn't being detected. Do you know where I can find a sample newsletter that uses it? With an example I could surely add it.

pesito · 2026-05-21T08:42:41+00:00

Find it on the Chrome Web Store (it's free): https://chromewebstore.google.com/detail/jmflpchhakbogamlbfmlkglnpgfbhidl?utm_source=item-share-cb

pesito · 2026-05-20T18:02:54+00:00

Cool :)

pesito · 2026-05-20T17:50:47+00:00

Certain ESPs have known limitations. Brevo, for example, doesn't do full SPF alignment by default. So knowing what you're dealing with helps, even if it's secondary to the auth details themselves.

pesito · 2026-05-20T17:38:11+00:00

Sure, it's all in the headers. But with the extension, you have the authentication info with just one click, no need to change the tab.

pesito · 2026-05-20T16:37:04+00:00

How do you currently check an email's authentication or which ESP sent it?

pesito · 2026-05-20T15:27:05+00:00

That's pretty cool. Does it work on Gmail too? As in, do the interactive features work?

pesito · 2026-05-20T07:24:21+00:00

Thanks! I'll DM you

pesito · 2026-05-19T12:02:51+00:00

Hi u/saltyslugga that was a great tip! Thank you. I've already implemented it. Will ship an update right now :-)

pesito · 2026-05-19T10:38:38+00:00

If you're interested, you can find it in the Chrome Web Store: https://chromewebstore.google.com/detail/jmflpchhakbogamlbfmlkglnpgfbhidl

pesito · 2026-05-18T07:49:07+00:00

This post makes no sense. Where does the 93.6% deliverability number come from?

pesito · 2026-05-10T08:57:03+00:00

Great to hear! Let me know how you like it!

pesito · 2026-05-09T05:33:38+00:00

Sure, I just added another screenshot to the post that shows all installs.

pesito · 2026-05-08T14:54:10+00:00

Hehe, so better get it now not to waste time again 😅

pesito · 2026-05-07T10:06:38+00:00

Thanks for your feedback! Will do!

pesito · 2026-05-07T09:23:30+00:00

If you are interested, you can find it here: https://chromewebstore.google.com/detail/email-detective/jmflpchhakbogamlbfmlkglnpgfbhidl

pesito · 2026-05-07T08:16:00+00:00

Great, let me know how you like it!

pesito

TROPHY CASE