K-9 Mail is the best free email client for Android. It has a million ways to tweak, customise, alter, change, modify... It does POP3, IMAP, MS Exchange, push email, and it gives you full control over which mail folders to sync and which folders to leave alone.
The canine has been updated twice in December to kill a bunch of
Now if they would only clean up that ugly dogface of an app icon..
• K-9 Mail (Android Market)
• K-9 Mail (Google Code)