Got your email configured correctly?

Is your email properly configured? If you're not sure, read on — you'll learn what to set up, and why. How do I check? There are plenty of online tools that can check your domain.

Is your email properly configured? If you're not sure, read on — you'll learn what to set up, and why.

How do I check?

There are plenty of online tools that can check your domain. I recommend this one, but the choice is yours.

What is DMARC?

DMARC (Domain-based Message Authentication, Reporting, and Conformance) is a protocol that checks whether SPF or DKIM came back valid — and if not, what to do with the email. So what are SPF and DKIM?

SPF

SPF (Sender Policy Framework) is, in short, a protocol that checks whether an email was sent from the right server. If you specify that your emails can be sent from your server and, say, Outlook's servers, and someone tries to send mail from a different server, it won't be delivered.

DKIM

DKIM (DomainKeys Identified Mail) is, in short, a protocol that signs the email header. If the signature checks out at the recipient the same way it did at the sender, the email gets delivered; if not, it doesn't.

Why do we need so many protocols?

SPF, while not perfect, defends against the vast majority of attacks. It has one major weakness, though — it doesn't survive forwarding. That's why DKIM was created. DKIM also works very well, but neither of these protocols tells the recipient what to do with an email that fails authentication. That's what DMARC is for — it tells the recipient exactly what you specify.

Why start now?

If you don't have DMARC configured, now is the time. Google has decided that if an email's DMARC isn't valid, the email will not be delivered to any Gmail inbox.