Bulk sender check
Gmail and Yahoo require bulk senders to authenticate their mail. Enter a sending domain to check its SPF, DKIM, DMARC and MX records, with a plain-English fix for anything that’s missing.
What DNS can’t tell you
Gmail and Yahoo’s bulk sender rules go further than these records. These live in your mail and your sending reputation, not in DNS:
One-click unsubscribe. Marketing mail needs List-Unsubscribe and List-Unsubscribe-Post headers, and unsubscribes honoured within two days.
Spam complaints. Keep the rate Google Postmaster Tools reports below 0.3% — under 0.1% is the comfortable zone.
From-domain alignment. The domain in your From address has to match the one SPF or DKIM authenticates, which is what DMARC checks.
Reverse DNS. Each sending IP needs a PTR record that resolves back to it — usually handled by your sending provider.
TLS. Mail must travel over an encrypted connection; every mainstream provider does this already.
Read the guide
Gmail and Yahoo's bulk sender rules, in plain English
What Gmail and Yahoo have required of bulk senders since February 2024, what breaks if you miss a rule, and how to check your own setup.
Sending through Carrier Crow?
Every campaign carries the one-click unsubscribe headers Gmail and Yahoo ask for, whichever SMTP provider sends it. SPF, DKIM and DMARC stay on your domain, with your provider.
How sending works →