Emails from WHBMP are not arriving

1. Make sure General Settings > Mail has real SMTP details. By default mail is only written to a log.
2. Press Send Test Email. If it fails, the message shows why (host, port, encryption or credentials).
3. Check Settings > System Logs > Mail. "Failed" rows show the reason. "Sent" means the server accepted it; check spam folders and your SPF and DKIM records.
4. If your host blocks port 25, use 587 (TLS) or 465 (SSL) or a relay.
5. Queued mail is sent by the cron job, so check that it runs.

Full guide: Email and SMTP.