On Tue, Feb 12 2013, David Bremner <david@tethera.net> wrote:
> Unfortunately currently headers other than those references in the
> notmuch-search-terms man page are not indexed.  The only workaround I
> can think of without patching notmuch is to use some tool to tag the
> messages you care about.

I think even more importantly headers other than those that are parsed
are actually thrown to /dev/null.  They are not even indexed as plain
text, so you can search for terms in headers as you can for words in the
body.

I asked this on irc but it got lost in the shuffle: would it make sense
to index the entire header block as plain text?  If we did that then at
least the search that Michal was trying would return the expected
results.  It would also be a fairly simple change to the indexer.  I
don't have a good sense of how much it would pollute the index, though.

Given how frequently people are asking for alternate header indexing, it
might be something to consider.

jamie.