bpo-38698: Add a new InvalidMessageID token to email header parser. (GH-17503)


This adds a new InvalidMessageID token to the email header parser which can be
used to represent invalid message-id headers in the parse tree.
(cherry picked from commit 68157da8b42b26408af5d157d2dba4fcf29c6320)

Co-authored-by: Abhilash Raj <maxking@users.noreply.github.com>
3 files changed