The following Mac Eudora plug-ins are available here:
Personalities_Ports Allows you to change ports, etc. per-personality. Updated October 24, 2001
Special_Tweaks Updated October 24, 2001 Allows you to set a few of my favorite special Mac Eudora tweaks:
Every this many seconds, Eudora automatically and silently saves messages that you're editing.
When you get email addresses using directory services or email, and they have a phrase of the form Last, First Eudora reformats them to First Last. This is especially helpful when dealing with addresses generated by certain products from a large and well-known company, in the form "'Last, First'".
Eudora only colors the label column instead of the entire row.
Command-clicking on an HTTP URL opens the URL in your browser, but does so in the background (so you can continue reading the email) and in its own window.
Supposedly, spool items get deleted after this many days. Not sure it's properly working, though.
Download the file, decompress it, and drag into your Eudora Items folder. Quit and relaunch Eudora.