Being able to group (the totally awesome) newsletters by different field

First, let me say – the newsletter thing is absolutely amazing. You literally solved a problem I was working around that day. 

Many of my newsletters are mailing lists in one way or another. They have mailing list x-tags:

List-Id: mailing list for ConTeXt users <>

and … oh, the other one doesn’t have the headers. Of course not.

In any event, I’d like to be able to (having inspected originals) train on consistent, but arbitrary headers. the to: field, or the list field (if it exists). or a subset of subject. Such that multiple people can be sorted into the same "feed"

Also, as a personal (most likely derp) – I can’t figure out how to rename incoming newsletter feeds, otherwise I would have tried renaming to smush them all together.

In any event, a bloody wonderful feature.</>