Claris Emailer Lite will load some of its parameters from the pre-configured Internet Config database. The Internet Config database is the Internet Preferences file in the Preferences folder. When used in a dialup configuration, the Apple Internet Dialer populates the Internet Config database with appropriate entries. However, when used in a LAN configuration, the required fields (email address, pop server, and so on) are not entered into the database, and this information cannot be edited using the Emailer Lite application.
The Internet Config application, distributed with AICK (in the Internet Utilities folder), can be used to set these needed preferences. The Internet Config application has clear and extensive balloon help if it's unclear what to enter in the fields. Once you have made the entries in Internet Config application, Claris Emailer Lite loads these parameters from the Internet Config database the next time Emailer Lite is launched.