BuddyPress.org

I have tested the site and I’ve found that this is not a BP problem.

I believe that the problem is caused because WP checks that the e-mail account is valid.

Being a local/virtual domain, I think that WP does not find some kind of record (on Internet) and this avoids WPmu to go on with the sign up process.

I will come back to share the solution when I success fixing it.

Greetings.