I want to install a Linux email gateway in front of our Lotus Notes
email server.  

While most of the users are internal some of them are external and use
pop to download email and SMTP to send email from home using the Lotus
Notes server as the SMTP server.  

If the email gateway is placed in front of Lotus Notes server to send
and recieve email via pop would there be any foreseeable problems? 
Basically they connect to the email gateway there password is checked
and if good then they can download email via pop or send email via
smtp.  

This email gateway is going to be for smtp messages sent to our domain
and we want to use it for users checking via pop and sending messages
via smtp.  

Can a Linux email gateway be prompted to only allow through email once
they have authenticated via pop or to prompt for a username and password
and it could use the same username and password they are using for pop.





Jim