Hi ! my be you can help me... Connection over the Internet to POP3/SMTP: I have one Exchange Server and an additional on as a Frontend server where all external User will take their EMAIL from. POP3: is working fine ... all EAMIL will be received SMTP: Sending Mail to internal People will work fine. Sending mail to non Exchange People will fail. Anyone any Idea... Sending EmAil from inside the Network to Internet is working fine. Btw. Frontend Server has an ISA2004 on it. Do you have any hint for me because im lost .... Thanks in advance Alexander