Re: Another activation issue.
Nearly always a server config issue or a email account one i.e no dns records for account, or a control panel such as plesk playing it’s tricks with email settings enabled but directing to a record that isn’t setup.
First thing is to disable BP and just get WP working and sending correctly. use an email account that has definite and legitimate credentials so that email servers don’t reject it due to no lookup records.
You might want to pas this by your server hosts for help with.