Mail servers (MX)
Looks up the servers that receive mail for your domain, so replies have somewhere to go, and reads which email service you use.
Are my emails set up right?
SPF, DKIM and DMARC Checker
Type your business domain. Get a plain-English list of what to fix, the exact line to paste, and where to paste it.
- Free, no sign-up
- Nothing you type is stored
- Every rule shows its source
What the checker looks at
Each check rests on an email standard or on Gmail’s and Yahoo’s published rules for senders, not on studies. A lookup that cannot finish is marked Not checked, never failed.
SPF
Sender Policy Framework is one line that lists who may send email as your domain. We check there is exactly one, that it includes your email service, that it ends in ~all or -all, and that it stays under the limit of 10 DNS lookups.
DKIM
DomainKeys Identified Mail signs each email so mailbox providers can tell it is really yours. We look in the spots your email service uses. A key can sit under any name, so not finding one is Not checked, never a fail.
DMARC
Tells mailbox providers what to do with mail that fails your other checks, and where to send reports. We read its policy and say the safe next step.
Questions
What do SPF, DKIM and DMARC do?
They are three short records in your domain's DNS that prove email from you is really from you. Sender Policy Framework (SPF) lists the servers allowed to send as your domain. DomainKeys Identified Mail (DKIM) signs each message so it cannot be faked or changed on the way. Domain-based Message Authentication, Reporting, and Conformance (DMARC) tells mailbox providers what to do when a message fails, and sends you reports.
Do I need all three?
Since February 2024, Gmail and Yahoo ask every sender to set up SPF or DKIM, and bulk senders (Gmail counts 5,000 or more messages a day to its users) to set up both plus DMARC. Most businesses set up all three, because they take a few minutes and missing ones are a common reason email lands in spam.
Why does it say DKIM is Not checked?
A DKIM key lives under a name called a selector, like google._domainkey, and only your email service knows which one it uses. We look in the spots your service uses. If we find nothing there, your key may still exist under another name, so we say Not checked instead of failing it. The steps in the DKIM tile turn it on if it was never set up.
What is the 10-lookup limit for SPF?
Each include: in an SPF record makes the receiving server look up another record, and those can include more. The SPF standard stops at 10 lookups, and past that the check fails for every email you send. It happens when several services are added over the years. The checker counts them for you.
Which DMARC policy should I start with?
Start with p=none. It changes nothing about delivery and starts the daily reports, so you can see who sends email as your domain. When the reports show your real email passing for a few weeks, move to p=quarantine, then to p=reject.
Is it free? Do you store my domain?
It is free with no sign-up, and nothing you type is stored or logged. We look up only public DNS records for the domain. We never contact a mail server and never send an email.
Every source is on the sources page, labeled as a standard or a mailbox provider rule.
Want one record explained in depth? See the SPF Checker, the DMARC Checker and the DKIM Checker.
Setup looks good? Check the email itself
The Free Sales Email Grader grades your subject and body against published sales research and several sales methods, and suggests a rewrite.
Try the Free Sales Email Grader