v0.22.2

• Editing a mail account with sending on says what went wrong. When the outgoing (SMTP) check failed while you saved an IMAP account, Brain answered "Mail setup is unavailable right now" and saved nothing. It now names the problem, such as a refused sign-in, so you know whether to fix the password or the server.
• Brain now notes why a mailbox stops syncing. When the mail server refuses part of a sync, Mail writes the reason to its service log instead of retrying silently, so a mailbox stuck on its first rebuild can be diagnosed.