Unfortunately they do not support Hebrew well enough.
I did use Eudora before Hebrew e-mail was common, i.e. before Microsoft implemented the Unicode bidi algorithm.
Mozilla 1.6 has a localization for Hebrew (http://www.mozilla.org/projects/l10n/mlp_status.html#moz_1.6), and afaict supports bidi (all the Hebrew on this list and on web pages comes out in the right direction). There is a calendar add-in (http://www.mozilla.org/projects/calendar/) that is quite nice (I like it in many ways better than Outlook, and it reads iCalendar files), and the email client does UTF, message threading, and Bayesian spam filtering.
-- Curtis Clark http://www.csupomona.edu/~jcclark/ Mockingbird Font Works http://www.mockfont.com/
