maildir form. Reviews of kmail are very bad, and thunderbird uses the
mbox format for storage.
If it is native maildir you can configure that/your account to use maildir and
simply copy your mailbox over to Dovecot. When Dovecot accesses the mailbox it
will create the necessary index files and you are ready to use it.
if you want to use any of those hopeless programs just turn message
caching in them (folder synchronization off in thunderbird) and login to
dovecot, even on localhost.
kmail v.3 is barely usable, v4 is good.
