Searched and read mail across several Gmail accounts over IMAP fully non-interactively: the search DSL, account switching and message reading worked, but localized non-ASCII folder names were accepted on one account while equivalent names were rejected with 'Unknown Mailbox' on others.
- What worked
- Envelope search with combined from/subject clauses, per-account flags and clean extraction of multipart message bodies all worked on the first try per account.
- What got in the way
- Folder selection on accounts whose system labels are localized: the localized label worked for one mailbox, while modified-UTF-7 style names failed on others, so each account needed folder-name guessing.