What is SPF and why do we need it?

SPF is basically your email domain’s guest list — and the mail servers at the door are checking it like nightclub security.

What is SPF?

SPF (Sender Policy Framework) is a record you publish in your DNS that says:

“Here are the servers that are allowed to send email on behalf of my domain. Anyone else? Kick them out.”

It’s literally a list of approved senders.

So if someone tries to send an email pretending to be you — but from some random server — the receiving system checks your SPF record and goes:

“You’re not on the list. you’re not coming in.”

Why we need SPF

1. It stops spoofing (or at least makes it much harder)

Without SPF, scammers can use your domain to blast out phishing emails.
With SPF, their fake sender server gets flagged as unauthorised.

2. It helps your real emails get delivered

Mail providers love SPF.
If they see you’ve got a proper SPF record, they’re more likely to treat your messages as legit and less likely to put them into spam.

3. It’s required for full authentication

SPF + DKIM + DMARC is the holy trinity of “please don’t send my emails to spam.”

DMARC in particular uses SPF results to make decisions, so without SPF your DMARC setup is basically missing a leg.

4. It helps you keep track of who’s sending what

Whenever you add a new email system — e.g. Microsoft 365, a marketing platform, a ticketing system — you add it to your SPF record.
This stops surprises and keeps your domain tidy.

The takeaway

SPF tells the world which machines are allowed to send mail as you.
Without it, your domain is free real estate for spammers, and your delivery rates suffer.