Every check a mailbox provider runs — in one honest score.

Is the connecting IP authorized to send for your envelope domain?

We resolve your SPF record, count its DNS lookups (the 10-lookup limit trips more senders than you'd expect), and confirm the sending IP is authorized. A permerror or a missing record is one of the most common reasons mail is rejected or filtered.

Does the cryptographic signature verify?

We find your DKIM keys by selector, verify the signature against the message, and read the key strength. A broken or missing signature means receivers can't prove the message wasn't altered — and DMARC can't pass on DKIM.

Do SPF or DKIM align with your From domain's policy?

We read your published DMARC policy (none / quarantine / reject), check whether SPF or DKIM align with the From domain, and confirm where aggregate reports are sent. Alignment — not just a pass — is what decides placement at Gmail, Yahoo, and Microsoft.

Is your IP or domain on a DNSBL?

We query your sending IP and domain against the DNSBLs that actually influence reputation. A listing can quietly divert your mail to spam long before you notice a drop in engagement.

How does a full spam engine rate the message?

We run the message through a complete spam-scoring engine — the same class of rules a mailbox provider applies — and surface every rule that fired, with its weight, so you fix what actually costs you.

Does the message have what inboxes expect?

We check for a List-Unsubscribe header (and one-click unsubscribe), a plain-text alternative, a valid Message-ID and Date, and the structural headers bulk senders are now required to include.

Are your links clean?

Every linked domain in the message is checked against URI blocklists — a single listed tracking or redirect domain can sink an otherwise-perfect message.