Still not working. I did find the filter itself in the file /plugins/buddypress/bp-core/bp-core-activation.php:
add_filter( ‘wpmu_welcome_user_notification’, ‘bp_core_disable_welcome_email’ );
I suppose I could just delete that line to remove the filter, but then every time BP is updated it’ll probably get overwritten and I’ll forget all about it. Not sure why your filter hook didn’t work. Any ideas?
Thanks a million for your help — I really appreciate it.