- Use RFC 2047 encoded-word for non-ASCII attachment filenames instead of
RFC 2231 filename* segments, which Coremail Web fails to display.
- Build multipart messages with MIMEMultipart when attachments are present
to keep address headers and attachment filenames Coremail-compatible.
- Add --attach support to reply and forward commands.
- Quote the original message body in reply drafts for proper threading.
- Add `mail download` to save attachments by IMAP UID
- Switch inbox/read/reply/forward to real IMAP UID (stable across sessions)
- Add MIME header decoding for non-ASCII filenames
- Add safe_filename() to prevent path traversal
- Use readonly mode for inbox/list/read to avoid marking unseen
Zhengshou Lai