Just edited my post.

Beginner here...

I would just stick the mail for now then 

I already made it displays my forum name first...

I will come back for this when am less busy

Thanks for the quick response

All emails (excerpt user registration) related to forum, are sent from the Email you configured in the Forums > Settings > Emails admin page. User registration process is under WordPress control, not wpForo. wpForo only provides with registration form, other processes are performed by WordPress. And yes, this is a known issue of WordPress. This is the default WordPress email. You should change it using some hooks like this:

add_filter( 'wp_mail_from', function( $name ) {return '***info@mydomain.com***' ; } ) ;
add_filter( 'wp_mail_from_name', function( $name ) {return '***My Forum name***' ; } ) ;

Change the red marked strings and put this code in your current active theme functions.php file. Make sure you hadn't deleted the apostrophe before and after the strings.

More info about this issue: http://www.wpbeginner.com/plugins/how-to-change-sender-name-in-outgoing-wordpress-email/

Please it is very urgent

At the dashboard side I already change the name to my site name but still it not working

Thanks....

@chris @robert