What does an SPF checker do?
An SPF checker looks up a domain's SPF TXT record and reports which servers are authorised to send mail for it, plus common problems like a missing record, too many DNS lookups or a permissive +all. SiteGuard Monitor's checker shows SPF alongside DMARC, SSL, DNS, uptime and security headers in one explainable risk score.
A broken or missing SPF record hurts email deliverability and makes a domain easier to spoof. This free SPF checker shows the published record and flags the issues that quietly send legitimate mail to spam.
Where SPF goes wrong
SPF is easy to get subtly wrong: more than ten DNS lookups, multiple records, a leftover +all or a missing include for a new mail provider. Any of these can break authentication without an obvious error, so messages just start landing in spam.
- Exceeding the 10 DNS-lookup limit breaks SPF entirely
- Two SPF records on one domain is invalid
- A trailing +all authorises the whole internet to send as you
What this SPF checker reports
- Whether an SPF record exists and is unique
- The authorised senders and includes
- The all mechanism (-all, ~all or the risky +all)
- Lookup-count and syntax warnings in plain language
Check SPF and DMARC together
SPF only does its job when paired with DMARC. This tool runs a full free scan, so you also see the DMARC policy, SSL certificate, DNS records, uptime and security headers — combined into one 0-100 risk score that prioritises what to fix.
Keep email authentication healthy over time
Mail providers change, includes get added and records drift. Add a domain to SiteGuard Monitor and you'll get an alert the moment SPF changes, with the status captured in every branded client report.
- Continuous monitoring of SPF and DMARC records
- Instant email and Discord alerts on changes
- Email-security health shown in monthly reports
Passive, read-only lookups
An SPF check is a read-only public DNS lookup — the same thing a receiving mail server does. SiteGuard sends no email and changes nothing on your domain.