If you have any suspicions on, change all the password and account, and in the current mailbox. In any case, set a new password on the mailbox that you want to attach the account. Make three different passwords.
Login to your personal account. Open the "Settings" tab, on can be intermediate the tab "settings access" or "security setting". Click on it.
Scroll down to the option "Change mailing address" and type in the new address. Save the settings.
If necessary, confirm the change your mailing address, received a letter on old and new mail addresses from the website. The messages will be links that will need to go. Only after this change, the email will come into force.