Changing “from” email address for user registration

I searched the forum for a answer to this question, but I couldn’t find any.

Everytime a new user register on my blog, he receives an email asking him to confirm the registration and then another one telling the registration was successful. I thought this email would be sent by the admin email, but it isn’t. Actually, it is sent by a strange email ([email protected]). Obviously, my blog host is Bluehost, but I would like my readers to view a friendlier email address in the from field.

I noted that emails sent from my backup plugin come from this same email address.

How can I change that? Is is a setting at WordPress admin panel or on my server itself?

Thanks,
Rafael Perrone