3.  Click  Only  the  list  below,  click  Add,  and  then  add  the  IP  of  your 

mail server that will be forwarding the mail to this server. You can 

specify a single computer, group of computers or a domain: 

a)  Single computer: Specify one particular host that you want to 

relay  off  of  this  server.  If  you  click  the  DNS  Lookup  button, 

you can lookup an IP address of a specific host. 

b)  Group  of  computers:  Specify  a  base  IP  address  for  the 

computers that you want to relay.  

c)  Domain:  Select  all  of  the  computers  in  a  domain  by domain 

name  that  will  openly  relay.  This  option  adds  processing 

overhead,  and might  reduce  the SMTP service performance 

because it includes reverse DNS lookups on all IP addresses 

that try to relay to verify their domain name. 

Step 5: Configure your mail server to relay mail via the mail 

relay server 

After you have configured the IIS SMTP service to send and receive 

mail, you must configure your mail server to relay all mail to the mail 

relay server. To do this; 

If you have Microsoft Exchange Server 4/5/5.5: 

1. Start up 

Microsoft Exchange Administrator

. 

2. Go to the 

Internet Mail Service

 and double click on it to configure 

its properties. 

The Microsoft Internet mail connector 

3. Go to the 

Connections t

ab. 

4.  Message  Delivery  section,  select   Forward  all  messages  to  host . 

Enter  the  computer  name  or  IP  of  the  machine  running  GFI 

MailSecurity. 

5. Click OK and restart Exchange server. This can be done from the 

services applet. 

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