Glossary
Glossary1 min read
DKIM (DomainKeys Identified Mail)
DKIM cryptographically signs each email so receivers can verify it is really from your domain and was not altered. A definition, with the full guide linked.
RT
RepMail Team
Product & Engineering · July 17, 2026 · 1 min read
DKIM (DomainKeys Identified Mail) attaches a cryptographic signature to every message you send. Your server signs with a private key; receivers verify with a public key published in your DNS.
A valid DKIM signature proves two things: the message came from your domain, and nothing in it changed in transit. Use a 2048-bit key.
See the full guide: Full guide: how DKIM works.
Resources in this guide
DKIM at a glance
Reference| Property | Value |
|---|---|
| Record type | DNS TXT/CNAME (public key) |
| Purpose | Sign and verify messages |
| Recommended key | 2048-bit |
dkim
authentication
dns
glossary
Frequently asked questions
How is DKIM different from SPF?
SPF authorizes the sending server; DKIM signs the message content itself, proving it was not altered. Receivers want both.
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