Mail records.

What we check

• MX records, which decide where your mail is delivered at all
• SPF, which lists who is allowed to send on your behalf
• DKIM, which signs your mail so recipients can verify it came from you
• DMARC, which tells receiving servers what to do when the checks above fail
• Whether these are actually passing, not merely present

Present is not the same as passing

A great many domains have all the right records and still fail. An SPF record that lists ten senders when the limit is exceeded, a DKIM key that was rotated at the provider but not in DNS, a DMARC policy set to reject while legitimate mail from a third-party sender fails the check. Each of these looks fine in a listing and does not work.

We report the outcome rather than the syntax. If your invoices are being rejected, that is what the alert says.

Why it stays broken for months

Nothing on your side changes. Your outbox says sent. There is no bounce for the most common failure modes, because the receiving server accepted the message and then quarantined it. The only signal is silence, and silence is easily mistaken for disinterest.

When you hear from us

Immediately if MX records disappear, if authentication starts failing, or if a DMARC policy tightens in a way that will begin rejecting your own mail. Otherwise weekly, as a line confirming your mail setup is intact.

What ends up in the record

Every change to every mail record, dated, with the previous values kept. When mail breaks, the first question is always what changed and when, and this is the only place that answer reliably survives.