How to make Netwrix Password Expiration Notifier notify users who do not have an email account in the managed domain?
Netwrix Password Expiration Notifier takes the email address (that is used for password expiration notifications) from the email field in the account properties General tab. The external email address can be manually specified (for example: John.firstname.lastname@example.org) for the user accounts that do not have an email account in the managed domain. They will be used for password expiration notifications.
In this scenario, Netwrix Password Expiration Notifier will use the managed domain SMTP server to send password expiration notifications to the external email addresses specified in the user account properties.
The SMTP server must have email relaying configured in order to send emails to external mailboxes outside the domain. Refer to the following information: