Does SPF alignment mean the same as DKIM alignment?

They sound similar, and they both feed into DMARC, but SPF alignment and DKIM alignment are not the same thing. They check different parts of your email against different identifiers.

SPF alignment compares the MAIL FROM domain (also called the envelope sender or return-path) with the From header domain your subscriber actually sees. If an email is sent from mail.deepcurrent.io but the From header says deepcurrent.io, SPF needs to pass on the right domain for alignment to hold.

DKIM alignment works differently. It compares the d= domain in the DKIM signature with the From header domain. If your ESP signs emails with d=deepcurrent.io and your From header shows captain@deepcurrent.io, that's aligned. If they don't match, DKIM alignment fails even if the DKIM signature itself is technically valid.

Here's the practical bit for DMARC: it only needs one of the two to align and pass. So if your SPF alignment fails (which happens often with forwarded email or when your ESP uses its own return-path domain), DKIM alignment can carry the whole thing.

The mode matters too. In relaxed mode (the default), the domains just need to share the same organizational domain. So mail.deepcurrent.io aligns with deepcurrent.io under relaxed rules. In strict mode, the domains must match exactly. Strict mode is tighter but also more fragile if you're using subdomains for sending.

So no, you don't need both to pass DMARC. But relying only on SPF alignment is risky because SPF alone has real limits. Email forwarding breaks SPF almost every time. DKIM travels with the message, so it survives forwarding intact. That's why having DKIM set up and aligned is genuinely worth the effort.

If you're not sure whether your alignment is actually passing, the free Email Header Analyzer at RME will show you exactly what's aligned and what's not. Worth a quick check before assuming everything is fine.