[courier-users] easy way to allow smtp auth ?

[Liam McAllister]

Hi   Pretty new to Courier so go easy on me!     i want to allow mail sending through the smtp server, but as most of the users are roaming I don't want to have to specify various IP address's. I also don't want to be an open relay.   What is the simplest way for me to provide this funcionality?   My set up -   Clean redhat 7.3, courier-0.39.3 with authdb, and maildrop   help appreciated   Thanks   Liam.