A convenience API unique to these bindings: compose an email through a std.Io.Writer and have it delivered into the database's mail root and indexed. Delivery goes through std.Io.File.Atomic so no partial file is ever visible, the maildir filename is generated (timestamp-prefixed like notmuch insert so names sort by arrival, plus 64 random bits), and an option chooses the new or cur subdirectory, cur getting the ":2," info suffix. cancel discards a partial message without a trace. The test fixture's newMessage now wraps the public helper, and tests cover cancellation, delivery to both subdirectories, the name format, and indexing round-trips. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017i7R7ReKJAHGQpitxGXqrb