If you get an SSL Certificate error, instructions for accepting the server's certificate are at,

Or you might want to do your email without encryption.  To remove encryption, go to the Tools menu and click Options.  Click on Sending Mail.  At the bottom, change "Secure Sockets on Sending" to "never".  Do the same for Checking Mail.

Changing ports in Eudora

 If you travel, and use many different ISPs along the way, some of them will block port 25 for outgoing email.  To avoid this, change your outgoing email port - our mail server uses port 366 as an alternate to 25.

First exit Eudora. Look in the Eudora directory for the folder "Extrastuff". In this folder there is a file named "esoteric.epi". Drag this file into the main Eudora directory. Restart Eudora then go to the Tools menu, Options, Ports, and change the ports here as needed.