SPF record checker
Ten DNS lookups might feel like plenty today, but it only takes marketing signing up for one new platform to push you to eleven. At eleven, your entire record breaks. Understanding the SPF ten-lookup limit is the first step toward reclaiming your DNS budget and keeping your mail delivered.
An SPF record lists the mail servers permitted to send email for your domain as a DNS
TXT record starting with v=spf1. Receiving servers test the sender's IP
against this list to decide whether to accept or flag incoming mail. Use our
SPF record generator to construct a clean
record.
Questions
What is the difference between -all, ~all, and +all in SPF?
With -all, unlisted senders fail SPF. With ~all, unlisted senders
get an SPF softfail. The receiver decides whether to accept or reject the mail. Tags like
?all and +all offer almost no protection. In fact,
+all tells the internet that every mail server is authorized to send for your
domain.
What is the SPF 10-lookup limit?
Under RFC 7208, an SPF record allows at most 10 DNS-querying mechanisms, including
include, a, mx, ptr,
exists, and redirect. This cap includes nested lookups inside
vendor records. Read our guide to the SPF 10-lookup
limit to see how quickly third-party includes consume your budget.
What happens when an SPF record exceeds 10 lookups?
Adding one extra provider can trigger a PermError. When that happens, SPF
validation fails completely. Every sender in your record loses its SPF pass, so SPF cannot
provide DMARC alignment. Check our directory of SPF records for
popular services and review common DNS errors.
How do you know which SPF includes are safe to remove?
Our tool resolves your full lookup chain so you can spot hidden includes before delivery
breaks. On a paid plan, we check your SPF record against 90 days of your aggregate reports
and mark every include keep, review, or remove based on the mail it actually
sent.
Stop reading raw DMARC XML reports by hand
Mailbox providers generate XML files containing IP addresses, volumes, and authentication pass rates for your domain. DomainCanary digests that data into one concise weekly summary, highlighting what changed and what needs attention. Your first domain is free, with per-source totals kept for the life of the account.
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