Email deliverability is derivative of email security. And here’s why:

Three key email security protocols are DKIM / SPF / DMARC. There are many others, but these three form the foundation.

DKIM verifies the sender's identity, SPF ensures emails are sent from authorized servers, and DMARC aligns DKIM and SPF with the sender's domain.

If you don’t have these on the server, your deliverability will suffer. Incoming email servers may recognize you as a scammer because scammers can’t implement SPF / DKIM when they spoof your emails.

This is why domain authentication is so important.

However, there are still tactics like DKIM replay, SPF replay, SubdoMailing that can be used to bypass the DMARC p=reject).

This is why, basic authentication records DKIM / SPF / DMARC p=none provided by email providers are just a temporary email deliverability solution. Because:

- DKIM keys must be regularly rotated;

- SPF must be built for the root domain & servers monitored;

- DMARC must be set to a strict compliance framework & monitored 24/7.

Without these fundamental steps, you leave the door wide open for scammers to break into your email server and start sending phishing from your email addresses.

The key takeaway: do domain authentication for email security, not just for email deliverability. Doing it solely for deliverability won’t enhance your security.