I tried to align my user names for my BOINC projects. As such I currently have two users for one project. Unfortunatly I registered here on my 'depreciated' user account.
I've already change email-Adress to the new account etc. in the hope that the email address will be used for new host when the sign in for a project.
But this did not work (ooes BAM use this magic key?). All new machines still get from BAM the depreciated user information.

Is there a way to "refresh" or update account information for a ressource/project? I would like new machines to use the new account.

Thanks for your help!

No, currently you cannot refresh your project information. In order to achieve the effect you want you must delete your current BAM! account and then create a new one with the 'new' e-mail. After that you must reattach all BOINC Clients to BAM! with your new credentials.