Domain health

Mailbox providers look at a few DNS records before they trust mail from your domain. The top of the dashboard shows, for every domain you send from, whether those records are in place, with a plain-language note on what to fix.

What it checks

Results are read from public DNS and refreshed every few minutes; Check again now re-reads them immediately. If a lookup itself fails the card says Unknown rather than claiming a record is missing.

SPF

Lists which servers may send for your domain. SubsiMail checks that there is exactly one SPF record, that it ends sensibly, and that it does not exceed the 10-lookup limit. Without a valid record mail is far more likely to land in spam.

DMARC

Tells receivers what to do with mail that fails the checks. A policy of p=none (monitoring only) is accepted and noted, since it satisfies the bulk-sender rules; once your reports look clean you can tighten it to quarantine.

DKIM

Signs your mail so receivers know it is really yours. Providers pick their own selector names, so SubsiMail tries the common ones. A provider that uses its own (Amazon SES uses random ones, for example) cannot be found this way, and the card says so: check that your provider's own setup page shows DKIM as verified.