Email checker methodology
What this tool measures, what it does not, and how a score or grade is produced.
What we measure
Public MX, SPF, a probe of common DKIM selectors, and DMARC TXT records via DNS. The score is a simple completeness check of those lookups.
What we do not measure
Inbox placement, sender reputation, content, volume, BIMI, ARC, or whether a DKIM selector we did not probe is valid. A high score is not a deliverability guarantee.
How we calculate this
Gmail and Yahoo have strengthened authentication requirements, especially for bulk senders. SPF or DKIM is expected broadly, while bulk senders are generally required to use SPF, DKIM and DMARC. The numeric score only reflects records we found in DNS β not whether Gmail or Yahoo will accept a specific message.