Procedure

1. Go to Administration → IMSVA Configuration → DKIM Signature.
   The DKIM Signature screen appears.

2. Click Enable DKIM signature and select one or multiple headers to sign.

   Note The From header is selected by default. To add more message headers for selection, click Customize.

3. Click Add.
   The Add DKIM Signature screen appears.

4. Specify the general settings.
   • Domain: Specify the domain where email messages are sent, for example, *.example.com.
   • SDID: Specify the signing domain identifier, for example, example.com.
   • Selector: Specify the selector to subdivide key namespace or retain the default value.
   • Private key: Upload a private key or request IMSVA to create a private key. If you want to generate a private key, select the key length before generation.
5. (Optional) Specify the advanced settings.
   • Header canonicalization: Select Simple or Relaxed.
   • Body canonicalization: Select Simple or Relaxed.

     Note Two canonicalization algorithms are defined for each of the email header and the email body: a "simple" algorithm that tolerates almost no modification and a "relaxed" algorithm that tolerates common modifications such as whitespace replacement and header field line rewrapping.

   • Enable signature expiration: If you select this option, set the number of days that the signature will be valid.
   • Enable body length: If you select this option, set the number of bytes allowed for the email body.
   • AUID: Specify the Agent or User Identifier on behalf of which SDID is taking responsibility.
   • Exempt domain: Specify one or multiple domains to be excluded from DKIM signing.
6. Click Save.