BuddyPress.org

everyone here is a volunteer and may not read every single thread or know the answer to every unique issue. probably does not help when being a bit off-putting.

All sign-up steps work until the confirmation message? what is the status in the users table for the failed signup user? does each failed signup user have an activation key in the usermeta table? if so – that at least tells us the bp_core_signup_user process works up bp_core_signup_send_validation_email (which only builds the email message and executes wp_mail() )

have a look in buddypress/bp-core/bp-core-signup.php at the functions and steps.

if you are using multisite, then it is a different process