Oftentimes, users of your site reports an issue that they aren’t able to receive any BuddyBoss or WordPress email such as activation email, notification email when a member sends a private message, etc.
What we may suggest is to try installing the below plugin to resolve the all-too-common problem of emails from WordPress sites going missing or ending up in spam folders as I tested the registration process on my own dev site using the latest version of the BuddyBoss Platform and Theme and it is working as expected.