Filtering on arbitrary headers

[romanofski]

This might be not something for a client, but rather for notmuch as a patch itself. But I thought we better track it.

The corresponding notmuch feature request is here: https://www.mail-archive.com/notmuch@notmuchmail.org/msg44527.html

[frasertweedale]

Nice to have. Remember that notmuch tagging hooks can tag messages according to such
properties.

[romanofski]

Oh really? Maybe this is not an issue at all? So you can match on X- headers and tag accordingly?

[frasertweedale]

On Wed, Jul 19, 2017 at 12:50:15AM +0000, Roman Joost wrote: Oh really? Maybe this is not an issue at all? So you can match on `X-` headers and tag accordingly?

Yeah. But it's an extra thing the user must configure, up front. I still think it would be nice to have the option to filter on arbitrary headers post-facto, even if it means nm has to build a custom index. But we depend on nm implementing that. Given the existing workaround I don't think we need to make this a baseline feature.