Question 1

What is an SPF record?

Accepted Answer

SPF (Sender Policy Framework) is a DNS TXT record that specifies which mail servers are authorized to send email on behalf of your domain. It helps prevent email spoofing and improves deliverability.

Question 2

How does SPF work?

Accepted Answer

When an email is received, the recipient's mail server checks the SPF record of the sender's domain. If the sending server's IP is listed in the SPF record, the email passes SPF authentication. Otherwise, it may be marked as spam or rejected.

Question 3

What does ~all vs -all mean in SPF?

Accepted Answer

'-all' (hard fail) means emails from unauthorized servers should be rejected. '~all' (soft fail) means they should be accepted but marked. '+all' allows anyone to send (not recommended). '?all' is neutral.

Question 4

How many DNS lookups can an SPF record have?

Accepted Answer

SPF records are limited to 10 DNS lookups (include, a, mx, ptr, redirect mechanisms). Exceeding this limit causes SPF to fail (permerror). Use ip4/ip6 mechanisms to reduce lookup count.

Question 5

Why is my SPF record not found?

Accepted Answer

Your domain may not have an SPF record published in DNS, or it may be misconfigured. Add a TXT record starting with 'v=spf1' to your domain's DNS zone. Changes may take up to 48 hours to propagate.