K-9 Mail + Productivity Android apps

K-9 Mail

free
            

The Android OS includes a Gmail app that gives you easy access to webmail, but K-9 is one of the few free email apps in the Market that provides access to both POP3 and IMAP accounts. Unfortunately, while it works as advertised, it seems to run very slowly, especially when downloading a lot of messages from heavily used inboxes.
We get a lot of email. When we tested K-9 on a very busy POP3 account, it pulled down the message headers and made a list of messages, but only with a long delay. When the program seized up, we found we could simply force it to quit, relaunch it and tell it to scan for new mail again. That's not pretty, but eventually it worked. Less heavy mail users might not have such difficulties.

If you don't use Gmail or a corporate Exchange server, K-9 is worth considering.