lost e-mails in cyberspace

[cpdtech]

HI everyone, I am using MS-Exchange 5.5

the problem is that when a staff member sends an e-mail and the recipiant replies to it, some of them arrive back to the staff member and other disapear in cyberspace. the have replied to it but it never turned up in the inbox. any suggestions where i have to look to fix a problem like that??

 

[zbnet]

Tell your user your support for the Internet finishes at the boundary of your network.

SMTP Internet messages are like postcards: everyone can read them and some don't get delivered.