Free deliverability tool
DKIM record validator
DKIM signs your messages so a receiver can prove they were not altered and came from someone holding your private key. The public key lives in DNS at a selector you choose. Most providers now hand you a CNAME so they can rotate keys without asking you to touch DNS again.
Worked example — sada._domainkey.example.com
Sample demonstration- PassSelector resolves
CNAME → sada.dkim.sadasend.net - PassKey type
rsa - PassKey length
2048 bitsComfortably above the 1024-bit floor.
- PassProxy status
DNS onlyProxying a DKIM record breaks the lookup entirely.
Valid 2048-bit key, resolving cleanly through a CNAME.
SadaSend runs these checks continuously on your sending domains, and refuses to send until they pass — so mail Gmail would reject never leaves.
Start freeWhat this checks
- The selector resolves and returns a key
- The record parses and the key type is supported
- Key length meets the 1024-bit minimum, 2048 preferred
- The record is not proxied — Cloudflare's orange cloud breaks DKIM
Questions
Other tools
- SPF checkerCheck an SPF record, resolve every include, and count DNS lookups against the limit of ten.
- DMARC checkerParse a DMARC record and explain what it actually does to mail that fails authentication.
- MX lookupResolve a domain's mail exchangers, check priorities, and flag common misconfigurations.
- Blocklist checkQuery major blocklists for an IP address or sending domain.
- Inbox placement testSend one message to seed addresses across major providers and see where it actually lands.