I run an Exchange 5.5 Sp4 under NT4 hosting emails for
multiple
domains. The email server is configured to accept only
SMTP for these specific domains, and it works quite well.
What I'm looking for is a way to have the SMTP server
reply with an
error 550 when a user does not exist for a local domain,
instead of
accepting the message.
When I send a message to john@mydomain.com, the email is
accepted in
the SMTP session, and later returned to the sender if
john@ does not
exist. This way, it looks like I accept email for any user
@mydomain.com.
Is there a way to return the 550 error in the MX SMTP
session, when
the message is for the local domain, but the user does not
exist?