During site setup, you designate at least one local domain for which Symantec Messaging Gateway accepts inbound email. You also define a single mail host to which the inbound Scanner routes email addressed to local domains. Any domain that is added during site setup is by default a local domain and uses this static route as its default relay to deliver inbound email.
After your site setup is complete, you can further configure inbound email domain acceptance to:
Reject or drop email addressed invalid recipients at specified local domains.
You must enable recipient validation for any domain for which you want Symantec Messaging Gateway to validate recipients or detect directory harvest attacks.
You configure a domain to validate recipient addresses within a local domain by configuring an LDAP recipient validation profile and enabling recipient validation on a per-domain basis. If recipient validation is enabled for a local domain, Symantec Messaging Gateway checks with the data source to determine that the email address exists in the LDAP directory. If there is no match, any attempted connection is rejected or dropped according to your site's settings for handling invalid recipients.