GMail is a web-based email system, is it not? Thus nothing to install?
For email use in LR, you need to know:
- server names
- server port numbers
- user name
- user password
- type of security protocol to use
Joe Gmail is Google mail which can be accessed through a web browser or by any currently available email client like Thunderbird, outlook, Apple Mac and a host of other email clients.
But you are right the OP need to know the server names, port # their username and the password for that username.