The article describes the process of setting up a policy which restricts users from sending messages to specific domains located outside your organization using Policy-based Encryption. To learn more about account-wide Policy-based Encryption, read the Knowledge Base article Getting started with Policy-based Encryption.
To restrict users from sending messages to specific domains you need to set up an email policy using Encrypted mail gateway.
- Log in to Encrypted mail gateway (CONTROL PANEL > Services > Compliance > Email Encryption > Encrypted Mail Gateway).
- Select Recipients & Sender Groups in Policies column.
- Click Add an Email List to create the list of the users which you want to restrict delivery for.
- Specify the list name, description, add each email address on a separate line and click Save.
Note: Recipient & Sender Groups accept only full email addresses. Domains alone will not work.
- Select Policies > Keywords & Dictionaries
- Click Add a Keyword / Dictionary List to create a list of domains users are not allowed to send to and click Save.
- Select Email Policies and click Add a Policy
- Set the following conditions:
If Sender contains Any from Recipients & Sender Groups list Sending Outside Prohibited
If Recipients contacts Any from Keywords & Dictionaries list Restricted Domains
Set Return to Sender to generate bounceback message and click Save.
- After you enable the policy users will receive the following message when trying to send to the recipients at restricted domains: