Hello and thank you for choosing JUSTANSWER.com
Bad news about Eudora.....
Eudora OSE is an email client that combines Mozilla's Thunderbird with code, features, and GUI elements from Qualcomm's Eudora.
We must assume that qualcomm no longer distributes the installers for Eudora.
SImply because the different versions INSTALLERS are no longer availabel for DL.
So, the only way would be through a torrent, or from somebody who DL'd that version, and is making it available online....somehow.