Policies - Forwarding Address Configuration

This article contains information on configuring Mimecast Forwarding Address policies, including steps to redirect emails to alternate addresses, usage considerations, policy settings, and ensuring forwarded messages are processed securely and archived according to retention policies.

In certain scenarios, you may require that messages to and from a specific email address are not delivered to the original recipient but instead delivered to an alternate address. Using a Forwarding Address policy, the Envelope To address is rewritten, and the message is delivered to the Forwarding Address only.

Usage Considerations

Consider the following before getting started:

• The Forwarding Address policy can alter the destination address for a particular mail flow. You can choose to have mail delivered to the original recipient in addition to the alternative address.
• The Forwarding Address must be an existing, valid email address (internal or external). We will determine whether the new recipient (Forwarding Address) is internal or external and deliver the message to this address. Any policy match will override the default delivery route.
• Details regarding the original recipient and the forwarded recipient are retained in the email headers, which can be accessed using an archive search.
• Forwarded emails are still processed by our security systems, including content, spam, and virus checks.
• Message contents are archived normally, according to your account retention period.

Configuring a Forwarding Address Definition

To configure a Forwarding Address definition:

1. Log in to the Mimecast Administration Console.
2. Navigate to Policies | Gateway Policies.
3. Click on the Definitions drop-down.
4. Select the Forwarding Address definition type from the list.
5. Either click on the:

• • New Definition button to add a definition.
  • Definition to be changed.

6.  Complete the Forwarding Address definition as follows:

Field / Option	Description
Policy Narrative	Provide a description for the policy to allow you to easily identify it in the future.
Forwarding Address	Use the Lookup button to select the address that you want emails to be directed to. This must be a valid email address.
Original Recipient	When enabled, the forwarded item will also be delivered to the original recipient.

7. Click on the Save and Exit button.

Configuring a Forwarding Address Policy

To configure a Forwarding Address policy:

1. Log in to the Mimecast Administration Console.
2. Navigate to Policies | Gateway Policies.
3. Click on Forwarding Address.
4. Either select the:

• • Policy to be changed.
  • New Policy button to create a policy.

5. Complete the Options section as required:

Field / Option	Description
Policy Narrative	Provide a description for the policy to allow you to easily identify it in the future.
Forwarding Address Definition	Click on the Lookup button to display a list of Forwarding Address definitions. Click on the Select link to the left of the definition to be applied when this policy is triggered.

6. Complete the Emails From and Emails To sections as required:

Field / Option	Description
Addresses Based On	Specify the email address characteristics the policy is based on. This option is only available in the Emails From section. The options are: The Return Address (Mail Envelope From): This default setting applies the policy to the SMTP address match, based on the message's envelope or true address (i.e., the address used during SMTP transmission). The Message From Address (Message Header From): Applies the policy based on the masked address used in the message's header. Both: Applies the policy based on either the Mail Envelope From or the Message Header From whichever matches. When both match, the specified value the Message Header From will be used.
Applies From / To	Specify the Sender characteristics the policy is based on. For multiple policies, you should apply them from the most to least specific.  The options are: Everyone: Includes all email users (i.e., internal and external). This option is only available in the Emails From section. Internal Address: Includes only internal organization addresses. External Address: Includes only external organization addresses. This option is only available in the Emails From section. Email Domain: Enables you to specify a domain name to which this policy is applied. The domain name is entered in the Specifically field. Address Groups: Enables you to specify a directory or local group. If this option is selected, click on the Lookup button to select a group from the Profile Group field. Once a group has been selected, you can click on the Show Location field to display the group's path. Address Attributes: Enables you to specify a predefined Attribute. The attribute is selected from the Where Attribute drop-down list. Once the Attribute is specified, an attribute value must be entered in the Is Equal To field. This can only be used if attributes have been configured for user accounts. Individual Email Address: Enables you to specify an SMTP address. The email address is entered in the Specifically field.

7. Complete the Validity section as required:

Field / Option	Description
Enable / Disable	Use this to enable (default) or disable a policy. If a date range has been specified, the policy will automatically be disabled when the end of the configured date range is reached.
Set Policy as Perpetual	If the policy's date range has no end date, this field displays Always On, meaning that the policy never expires.
Date Range	Use this field to specify a start and/or end date for the policy. If the Eternal option is selected, no date is required.
Policy Override	This overrides the default order that policies are applied. If there are multiple applicable policies, this policy is applied first unless more specific policies of the same type are configured with an override.
Bi-Directional	If selected, the policy is applied when the policy's recipient is the sender and the sender is the recipient.
Source IP Ranges (n.n.n.n/x)	Enter any required Source IP Ranges for the policy. These only apply if the source IP address used to transmit the message data falls inside or matches the range(s) configured. IP ranges should be entered in CIDR notation.

8. Click on the Save and Exit button.

Internal emails that are sent and received within the same organization do not route through the Mimecast gateway, which means they do not automatically trigger forwarding policies. For internal email forwarding, you may need to utilize Microsoft Exchange forwarding directly within your email system.