Hi people. I really hope somone can help me, im tearing my hair out here! Ive got an exchange server 2003 mailserver running behind a Cisco 1721 router, and for the life of me I cant access the mailserver from outside. Ive implemented the following commands with no success.... ip nat inside source static tcp 192.168.0.6 25 interface Dialer0 25 access-list 101 permit tcp any host 192.168.0.6 eq smtp access-list 102 permit tcp any any eq smtp And it wont budge. I dont know a huge amount about the cisco's and this is for the small company I work for, and I feel a bit thick not being able to do this!! When telnetting the mailserver from inside, it works perfectly, so I know the SMTP service is running ok. Can anyone please help?