Test the configuration to verify communication between the mail server and Mail Express. Send emails to/from addresses that are internal (managed by the mail server) and external using the following criteria:
Email from the system - Send a test email using the Mail Express Mail Server Configuration page to a recipient internal to the mail domain and to one that is external to the domain. Verify that the messages are delivered and that the From and Reply to addresses are correct. (Mailbox monitoring must be off during the test, otherwise emails are sent to the mailbox being monitored.)
Email on behalf of a user - Send an email on behalf of users who have addresses both internal and external. The web portals can be used to execute these tests. You can either create internal and external users of Mail Express, using email addresses internal and external to the mail domain, or enable anonymous access to the Drop-Off portal and explicitly set the email addresses.
Email on behalf of an internal address - Send an email from an internal address to an internal address and an external address. Verify that the messages are received.
Email on behalf of an external address - Send an email from an external address to an internal address and an external address. Verify that the messages are received.