DKIM Test
This tool tests your DomainKeys Identified Mail (DKIM) setup. Send a test email to a generated address and get insight whether the email contains a valid DKIM signature. Additionally, the tool checks the DKIM signature for identifier alignment to the sender From domain as required by DMARC.
Send email or upload .eml file
Test Method
Test results can be retrieved later by entering the email address generated for the test. If you send multiple emails to the same test address, only the first one will be evaluated and shown. Results will be purged after one week. The test will yield no result if the email is rejected by my MTA on SMTP level, e.g. due to an invalid sender address. Files uploaded via the web interface are not stored on the server.
The test will be successful if any DKIM-Signature in the email is verified correctly and the email passes identifier alignment. The test uses the dkimpy library for DKIM verification as shipped by Debian in package python3-dkim. When testing with dkimpy by yourself, beware that by default it verifies the topmost DKIM-Signature occurrence only.
The identifier alignment used in the test is not part of the DKIM specification (RFC6376); an email may pass the DKIM validation, even if the identifier is misaligned. The identifier alignment is required by DMARC (RFC7489). However, the test does not attempt DMARC validation.