Changing of the Welcome-Email in the administrator portal

[Hatrix]

Hello again,

my client asked us as well if it is possible:

a) to create the Text for the welcome mail to be sent in the administrator protal

and

b) if it is possible on account-creation to uncheck a checkbox if they do not want to send a welcome mail to a particular client (for whatever reasons).

Is this possible? Maybe as a zimlet? Are existing solutions out there? Or do we have to write a Zimlet on our own if this is possible to do with a Zimlet?

thanks