I’ve been working on this, and it seems that the only thing not working now is when an admin sends an email to everyone in the group. I have gotten the others to work.
I tested non-BP emails, like lost password, and got that just fine, so it’s just BP emails not sending. No user signup notifications or group digests at all, when they worked fine last week. I did nothing but upgrade the plugins since.
Sorry, latest versions of both WP and BP, not on bluehost. Seems that SMTP is not “seeing” the email it’s supposed to send from, saying it’s blank, so it’s not an authorized user.