Suggestions for e-mail client:

[R. G. Newbury]

I have been using thunderbird but unfortunately it saves all the 
messages in one large globular file. I cannot merge e-mails which have 
been retrieved/sent from different computers into one source.
I like the way thunderbird works, otherwise.
I need an e-mail client which keeps messages as single items (files) and 
which can rebuild its indexes of the messages in each folder without 
painful interventions, so that I can merely rsync the appropriate folder 
structure into one place for a full backup of all computers.
(I have had these features for years using pmmail in OS/2 but I have 
made the switch and will not go back..but I do miss some things.)

Suggestions please.