Outbound Rules

When are outbound rules applied?

Outbound rules apply whenever a message is sent from your domain. They enable:

• Encryption: Only the intended recipient can read the message.
• Signature: The authenticity and integrity of the message are verifiable.

Guide: Create an Outbound Rule

1. Create a New Route

• Open the "Routing" menu and click "+".
• In the first step, select "outbound".

2. Select Security Protocol

• Decide which protocols should be used (multiple selection possible):
  • S/MIME: Certificate-based encryption and signing
  • PGP: Key-based encryption and signing
  • Message portal: Secure communication without certificates or keys. Can be used as a primary option or as a fallback when no keys are available.

• Tip: More details can be found in the Cryptography section.

3. Define Sender and Recipient

• Determine which messages the rule applies to:
  • Custom: Specific mailbox or wildcard (*)
  • Group: Apply to a predefined group
  • All: All outbound messages are included

• Note: If you have not yet created any groups, follow the guide in the Groups section.

4. Configure Cryptography Options
Depending on the selected protocol, the following settings are available:

• Encryption:

  • Send without encryption
  • Encrypt if possible
  • Send only encrypted

• Signature:

  • Send without signature
  • Sign if possible
  • Send only signed

• Algorithms:

  • AES-128, AES-192, AES-256
  • SHA-256, SHA-384, SHA-512

• S/MIME encryption modes:

  • CBC (Cipher Block Chaining)
  • GCM (Galois/Counter Mode)
  • CTR (Counter Mode)
  • CFB (Cipher Feedback)
  • OFB (Output Feedback)

• S/MIME signature modes:

  • Cleartext (cleartext signature)
  • Opaque (opaque signature)

• PGP signature modes:

  • PGP/Inline
  • PGP/MIME

• Key management:

  • Use a specific certificate or key
  • Automatic selection from stored imports (default)

  Tip: If you want to use a specific certificate or key, import them beforehand in the Cryptography section.

5. Notifications

• Status indicators in the subject line of emails are only possible through your mail server.

6. Save Rule

• Review the configuration in the summary.
• Click "+" to activate the rule. It will then appear in the overview.

Important Notes

• Outbound rules apply exclusively to messages sent from your domain. External senders are not affected.

• Make sure that all required certificates or keys are stored in the "Cryptography" section.