Hello, Let me brief you the scenario what i have so that it will be clear to what i am talking of all about. 1.I have configured a server with Windows 2000 Server as a domain controller by setting up the DNS and i have one internal network card with the IP address as 192.168.1.201 and an external network card with the relevant IP address of the T1 line provider with respective gateway,DNS entries and all. 2.After that i have installed ISA server Standard edition with the Integrated Mode option selected. 3.I have also opened respective ports in IP packet filter rules such as POP3,SMTP and SSH in both direction ports are opened 4.when i am trying to telnet POP3 port it doesn't work but SMTP port does work. So could you pls let me know where am i going wrong .Can anybody help me in this scenario. Thanks Bhavesh Mehta