163/NetEase IMAP servers reject every UID SEARCH/FETCH with `BYE Unsafe
Login` unless the client first identifies itself via the RFC 2971 ID
command after LOGIN. Without this, the email gateway logs in OK but
then fails on the very first poll and the connection is torn down.
Send the ID payload best-effort after both `imap.login()` sites
(`EmailAdapter.connect` and `_fetch_new_messages`). Failures are
swallowed at debug level so non-supporting IMAP servers (Gmail,
Outlook, Fastmail, Yahoo, etc.) keep working unchanged.
Closes#22271
Wesley Simplicio
3fd4ccbd8b