Mail dkim

DKIM (DomainKeys Identified Mail) is a method of authenticating the sender of an email message. It uses a digital signature to verify that the email was sent by the claimed sender and that the message has not been tampered with during transmission.

Here's how DKIM works:

  1. The sender's email server generates a private key and a corresponding public key.
  2. The private key is used to sign the email message with a digital signature.
  3. The public key is published in the sender's DNS records, specifically in a TXT record.
  4. When the email is received by the recipient's email server, it retrieves the public key from the DNS record.
  5. The recipient's email server uses the public key to verify the digital signature.
  6. If the digital signature is valid, the recipient's email server knows that the email was sent by the claimed sender and that the message has not been tampered with.

Benefits of DKIM:

  1. Authentication: DKIM helps to prevent email spoofing, where an attacker sends an email that appears to come from a different domain.
  2. Trust: DKIM increases trust between senders and recipients, as it provides a way to verify the authenticity of the email.
  3. Delivery: DKIM can improve email delivery rates, as it helps to prevent spam filters from flagging legitimate emails as spam.

How to implement DKIM:

  1. Generate a private key: Use a tool like OpenSSL to generate a private key.
  2. Generate a public key: Use the private key to generate a public key.
  3. Publish the public key: Publish the public key in your DNS records, specifically in a TXT record.
  4. Sign your emails: Use the private key to sign your emails with a digital signature.
  5. Verify the signature: Use the public key to verify the digital signature on incoming emails.

Common DKIM record formats:

  1. TXT record: v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC...
  2. DKIM record: dkim._domainkey.example.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC..."
  3. SPF and DKIM record: v=spf1 a mx ip4:192.0.2.1 include:_spf.google.com ~all and dkim._domainkey.example.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC..."

Note: The DKIM record format may vary depending on the email service provider or the specific implementation.