If you have android phone and you want to access official emails on you phone, you might face some problem as pre-installed email application is very slow. It can’t retain all emails on the device for further communication.
For example if you have already downloaded email on your phone and outlook setting say “remove from the sever”, once you download all the emails in outlook, all emails will be deleted from the sever and simultaneously from the mobile because application does not save emails on the device.
K-9 Mail is an open-source e-mail client with search, IMAP push email, multi-folder sync, flagging, filing, signatures, bcc-self, PGP, mail on SD & more. Its supports IMAP, POP3 and Exchange 2003/2007. It very lite and has almost all features as gmail app.