Free tool
Is your domain ready to send?
One lookup, seven checks: SPF, DKIM, DMARC, MX, PTR, blocklist status, and MTA-STS — in plain English, with links that explain the fix. No sign-up.
What we check, and why it matters
SPF, DKIM, DMARC
The authentication trio every mailbox provider now requires from bulk senders — and Microsoft demands all three pass.
MX records
A sending domain that can't receive mail looks disposable. Receivers notice.
PTR / reverse DNS
The check most lists forget — and the top cause of Gmail rejections in the November 2025 enforcement wave.
Blocklists
Every brand-new domain starts its life on a blocklist for 24 hours. Here's why, and what else to watch.
What this tool can't see: your sending reputation and inbox placement are decided inside Gmail, Microsoft, and Yahoo — no external checker can read them. DNS readiness is the part you can verify. The other part is sending history, which is what WarmEnvelopes builds.