Deliverability

When it comes to email delivery, not all SMTP ports are created equal. While port 25 might be the oldest port in the book, and port 465 had its moment in the sun, it's port 587 that...

It's frustrating as an email sender when your messages don’t get through. Especially if you don't know why it's happening. In this article, we’ll dig into why Gmail may be blocking...

SPF doesn’t refer to how long you can wait before you have to reapply your sunblock (seriously, go get some). Instead, the term “SPF” refers to a security measure that helps...

Email deliverability sometimes feels like a mirage. Your messages go on a long journey from your mail server to your subscribers’ inboxes. But it’s the last part of that journey that...

Email authentication lets mailbox providers know that you’re a trusted sender – that you are who you say you are. As a Technical Account Manager at Mailgun, I’m constantly...

We’ve talked a lot about email bounces and email bounce rates as a whole in the past before, but we’ve really only ever dipped our toes into the different types of bounces...

Remember relay races in school? Just as runners pass along a baton, an SMTP relay passes along an email from one server to another. Sinch Mailgun’s free SMTP relay...

The moment Vesper Lynd slinks onto the screen in Casino Royale, you know exactly how this will all play out. Despite being a world-class spy, James Bond will fall hard for the...

The world of email is undergoing a significant shift. With Google and Yahoo recently increasing enforcement on DMARC, many organizations are having to implement DMARC...

Why do we need SMTP commands and what do they do? Well, we use SMTP (Simple Mail Transfer Protocol) commands to communicate with email servers. These commands are...