SPF (Sender Policy Framework) is a DNS TXT record that lists the servers allowed to send mail for a domain. Receivers check the connecting IP against that list during the SMTP transaction.
Does SPF alone stop spoofing?
No. SPF validates the envelope sender, which spoofers can set to their own domain while forging the visible From. DMARC closes that gap by requiring alignment.
What does ~all versus -all mean?
~all is softfail: receivers mark but usually accept. -all is hardfail: receivers may reject. Start with ~all, graduate to -all once DMARC data is clean.
How do I fix 'too many DNS lookups'?
Remove unused includes, replace includes with ip4/ip6 mechanisms where vendors publish static ranges, or use an SPF flattening service.
Why does SPF records matter for deliverability?
Without SPF, any server can claim to send as your domain. With a broken SPF record, legitimate mail fails authentication and lands in spam. SPF is also one of the two alignment paths DMARC relies on.
What is the first step to get started with SPF records?
Inventory every service that sends mail as your domain: your ESP, CRM, helpdesk, billing system, and internal mail server.
What is the most common SPF records mistake?
Exceeding the 10-lookup limit, which causes a permerror and effectively disables SPF.