SmarterMail versions 5 and 6

If you are able to login with the email address you need to change the password for.
Login to your webmail (usually - http://mail.yourdomain.com)
Click on "Settings" button at the top.
Expand "My Settings" on the left and click on "Account Settings".
Under "User" tab type your current password and then new password and click "Save" button at the top.

If you are NOT able to login with the email address you need to change the password for:
Login to your webmail (usually - http://mail.yourdomain.com) as [email protected] (password is usually the same as your default FTP password).
Click on "Settings" button at the top.
Expand "Domain Settings" on the left and click on "Users".
Right-click on the user you need to change the password for and click "Edit".
Under "User" tab type new password and click "Save" button at the top.

SmarterMail versions 3 and 4

If you are able to login with the email address you need to change the password for.
Login to your webmail (usually - http://mail.yourdomain.com)
Move mouse over the "Settings" at the top and click on "My Settings".
Click on "Mailbox" tab and type your current password and then new password. Click "Save" button at the top.

If you are NOT able to login with the email address you need to change the password for:
Login to your webmail (usually - http://mail.yourdomain.com) as [email protected]
Move mouse over the "Domain Settings" at the top and click on "Email Users".
Click on the user you need password changed for and under the "Mailbox" tab type new password and click "Save" button at the top.