Switchies For Mail
is a little Mac application that will let you switch from one set of mail account to another under the same user account over (Apple) Mail. Using Switchies For Mail, you can create and maintain different categories of Mail accounts without switching users. Why not separating business-related Mail accounts from personal Mail accounts? If you are sharing the same computer with somebody else, both of you can can have your own set of Mail accounts under the same user account. And you can switch from one set of Mail accounts to another with just a click of Mouse.
Switchies For Mail lets you save passwords and hand them over to Mail when it needs them. Mail can occasionally fail to access Keychain data and retrieve E-mail account passwords. If that happens, simply choose Mail > Tell Passwords to Mail.