email/imap -client software

This might lead to flaming war here, but despite that I'd like to know suggestions for good email-client software... I have used mozilla -mail, but it is really heavy, though I like it's user-interface and features, possible to handle many accounts, hendling attachments, integration to browser sometimes speeds things up etc I'd like to know what other good, stable graphical app thera are? needed: -light -graphical (my girlfriend also has to use that....) -can handle many imap accouts (no other protocols needed) -no need for news-group ability -can handle mail-threads -light -for linux of course ! -free Thanks, P_