Postmark

New Features for SMTP Field Manual

Here at Postmark, we believe email delivery shouldn’t be a mysterious black box. That’s why we created the SMTP...

I don’t blame you for asking. Honestly it sounds like a new Scandi-style furniture company, or maybe an...

Traditionally Postmark has focused on sending only transactional messages with the highest deliverability standards, and that’s produced a...

Oh, how I love tossing an IP into multirbl.valli.org, a true one-stop-shop to instantly check “all the things.” But...

Your message file size matters. Some may think it’s great to send a ton of content in one...

In the past couple of weeks, we’ve seen multiple customers report that their messages to Gmail/GSuite recipients are...

Your IP represents the sending environment, typically a shared IP owned by your email service provider (ESP). Knowing...

While IP reputation is still important, most people are sending mail over an IP shared with other senders....

We’ve all been there—that message you’ve been waiting for is finally found in the depths a Gmail spam...

Perhaps you’ve started a new business, you’re going through a branding shift, or maybe you’re just adding a...

We’ve all been there—that message you’ve been waiting for is finally found in the depths a Gmail spam...