Changing your password to protect your account is always recommended. Here are the guidelines for changing your password.
1. Create a password you'll remember (or write it down).
2. Don't make it easy to guess! (don't use your name, your kids, your company etc in the password)
3. DO mix capitals, small letters, numbers and symbols
4. Create a password at least 8 characters long
These guidelines are very important. Yours is not the only email on the server. Compromising one account can compromise everyone's account on the server.
To change your password:
Login to your email account: http://mail.YOUR-Email-domain
(for example: if your email is firstname.lastname@example.org than browse to http://mail.50bubbles.com then follow steps 1-4 in the graphic below.