SPF

What is SPF?

SPF (Sender Policy Framework) is an email standard that, as a TXT record in the domain’s DNS, states which mail servers and IP addresses may send email on behalf of the domain. Receiving servers look up the record and check whether the sending server is on the list. SPF validates the envelope sender (MAIL FROM / Return-Path) — not the visible From address the recipient sees.

Why does SPF matter?

Without SPF it is trivial for spammers to forge your domain as the sender, and your own emails land in spam more often. A correct record improves deliverability for both transactional emails and newsletters, and it is a prerequisite for DMARC to enforce sender alignment. SPF rarely stands alone: it is combined with DKIM and DMARC to actually protect against spoofing of the visible sender.

Common use cases

• When you send from your own domain via an email platform (e.g. Klaviyo or Omnisend) and need to add the provider’s include mechanism.
• When emails land in spam and you are debugging authentication failures.
• When you consolidate several senders (store, support, marketing) into one record.
• When you hit the limit of 10 DNS lookups, which otherwise triggers a permerror.

Shopify perspective

Shopify Email now authenticates your sending domain automatically via a set of CNAME records in your DNS, instead of you manually adding an SPF include. If you use third-party email apps, you often still have to add their SPF include yourself. Always verify the record after setup — a single TXT record per domain may resolve to at most 10 lookups.