thread-based email index, search, and tagging https://git.notmuchmail.org/git/notmuch/atom?h=nmweb 2018-09-06T11:07:13Z 2018-09-06T11:07:13Z David Bremner david@tethera.net 2018-08-30T11:29:14Z urn:sha1:b31e44c678bf3bfe81bcc5f159e627551f12700f The idea is that if a message-id parses with this function, the MUA generating it was probably sane, and in particular it's probably safe to use the result as a parent from In-Reply-to.