To ensure only messages destined for valid internal email addresses are accepted, we need to validate the recipients of all inbound email. Emails that can't be matched against a valid internal address will be rejected.
To set up recipient validation:
- Click the Gateway | Set Up Recipient Validation menu item.
- Either click the:
- Enable Directory Users Only button to only accept emails for addresses synchronized from your directory.This option is unavailable if you've not completed the Synchronize Your Directory step.
- Enable Known Addresses button to accept emails for all known addresses in your domains. This includes addresses synchronized from your directory, imported via a spreadsheet, and created manually.
- Enable Directory Users Only button to only accept emails for addresses synchronized from your directory.
A summary page is displayed showing your recipient validation setup.