Before you set up the Email you must set up the internet access setting (GPRS, WAP) check you web access works by doing a few searches on google. Once you have done this then you set up the email. I am using the gmail, but a similar method can be used to set up yahoo, or aol or . . . . whoever.
Basically this is the stuff you need to type in (FOR GOOGLE)
Go: Menu > Messages > Settings > Emails > Email Profiles
Choose the profile that you use to access the web, and save, the B2100 will tell you the profile is changed. . .good. Back out to main menu.
Go: Menu > Messages > Settings > Emails > Email Accounts
name the account with your full email adress, type in the information from the table above (if using gmail) remebering to double check everything, and enter the port settings.
For those of you that are used to the iphone and outlook these configuration setting will seem wofully complicated, but if you persist you will win.
Other Pop Settings
Yahoo Pop Settings
AOL Pop Settings