DKIM Explained: The Digital Signature Behind Business Email

The six points in the video

This is a silent video. The headings, explanations and labels below reproduce the information on screen.

1. 1

   Step 1: DKIM uses a digital signature

   0:18

   DomainKeys Identified Mail is the full name.

   On-screen labels: Signing domain; Digital signature; Email authentication.

2. 2

   Step 2: The sender keeps a private key

   0:30

   The sending service uses it to sign outgoing email.

   On-screen labels: Private signing key; Sending service; Protected configuration.

3. 3

   Step 3: DNS publishes the public key

   0:42

   Receiving servers use the public key to check the signature.

   On-screen labels: Public verification key; DNS record; Receiver check.

4. 4

   Step 4: A selector finds the right key

   0:54

   The message identifies which published signing key to use.

   On-screen labels: Signing domain; Selector value; Matching DNS key.

5. 5

   Step 5: Check each sending service

   1:06

   A website mail service may need its own authentication setup.

   On-screen labels: Mailbox provider; Form-mail provider; Separate setup checks.

6. 6

   Step 6: Keep the limits in mind

   1:18

   A valid signature alone does not prove a message is safe or wanted.

   On-screen labels: Authentication signal; Related SPF and DMARC; Still assess the message.

Common questions

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