Trend Micro InterScan Messaging Security DKIM Setup

Trend Micro InterScan Messaging Security DKIM Requirements

Step 1: Access the DKIM Configuration

1. Log in to the Trend Micro IMSVA admin console.

2. Navigate to:
   Administration → IMSVA Configuration → DKIM Signature

Step 2: Enable DKIM Signing

1. Check the box for “Enable DKIM signature.”

2. Select one or more headers to sign.

   • The From header is selected by default.

   • To add more headers, click Customize and choose the headers you want to include.

3. Click Add to begin DKIM configuration.

Step 3: Configure General DKIM Settings

In the Add DKIM Signature screen, fill in the required fields:

• Domain: Enter the domain to be signed, e.g. *.example.com

• SDID (Signing Domain Identifier): e.g. example.com

• Selector: Provide a selector (e.g. dkim1) or use the default

• Private Key:

  • Upload your own private key or

  • Have IMSVA generate one for you

  • If generating, select a key length (typically 2048 bits is recommended)

Step 4: (Optional) Configure Advanced DKIM Options

You may optionally configure the following:

• Header Canonicalization: Choose between Simple or Relaxed

• Body Canonicalization: Choose between Simple or Relaxed

• Enable Signature Expiration: Set a validity period in days, if required

• Enable Body Length: Limit the number of bytes allowed in the email body

• AUID: (Agent/User Identifier) — specify an identifier acting on behalf of the SDID

• Exempt Domains: Add any domains you want to exclude from DKIM signing

Step 5: Save Your Settings

1. Click Save to apply the DKIM configuration.

2. Your domain is now configured to sign outbound email using DKIM.