Installation instructions

GFI MailSecurity for Exchange/SMTP Installing GFI MailSecurity  15
Screenshot 5 - Relay Restrictions dialog
3. Click Only the list below and then click Add to specify the list of
permitted computers.
Screenshot 6 - Specify machines which may relay email via virtual server
4. In the Computer dialog box, specify the IP of the mail server that
will be forwarding the email to this virtual server and then click OK to
add the entry to the list.
NOTE: You can specify the IP of a single computer, group of
computers or a domain: