Free tool
See how your email authenticates
Send any message, from any system, to a one-off address. You'll see what a receiving mail server sees: SPF, every DKIM signature verified against the published key, DMARC alignment, reverse DNS and the unsubscribe headers Gmail and Yahoo require.
The address works for one hour. Only the headers and the verdicts are kept, for one hour, and the body is never stored. Don't send anything confidential.
Or paste a message you already have
Open the message, choose Show original (Gmail), View message source (Outlook) or Show all headers, and paste the whole thing here. Include the body if you want the DKIM body hash checked. Nothing you paste is stored.
Send an email from the system you want to test to:
Any subject and body will do. Testing a newsletter or app? Send a real campaign or transactional message to this address, so the headers match what your subscribers get.
Results
Message
DMARC
SPF
DKIM
Path and receiver
Something failing that shouldn't?
Book a free 20-minute review. I'll look at the results with you and tell you what to fix first, whether or not we work together.