> I forked Mu and let it store the “X-Debbugs-Envelope-To” header in the
> database:
>
>     https://git.elephly.net/?p=software/mumimu.git;a=shortlog;h=refs/heads/mumimu
>
> This seems to actually work.  Still don’t know if all emails actually
> have that header; if they don’t we’ll need to implement an alternative
> way to get the bug number in “get_bugid” (lib/mu-msg-file.c).

Can't we find the bug number of an email by matching the To and Cc
addresses against xxxxx@debbugs.gnu.org where xxxxx is a bug number?