Glossary

DKIM

DomainKeys Identified Mail: a signature your sending system adds to each message, which receivers check against a public key in DNS.

ValidReach Team · Updated 2026-10-26

In practice

The public key lives in a TXT record at a name such as selector._domainkey.example.test. A valid signature shows the message was authorised by that domain and that the signed parts were not altered in transit.

Verification and sending

DKIM covers the sender. It says nothing about whether the recipient address exists.