How to find mails which are sent to 'undisclosed-recipients' ?

[Austin Clements]

Quoth Vladimir Marek on Jul 11 at  8:03 pm:
> > > Since my mail works in a way that it hides everything but what I
> > > selected to be shown to me, I was overlooking all mails which where sent
> > > to undisclosed-recipients. I tried to match such mails by
> > > to:undisclosed-recipients but that does not seem to work. Is there any
> > > workaround to find such mails?
> > 
> > I have some mail with this To header:
> > 
> > To: Undisclosed recipients <Undisclosed recipients:;>
> > 
> > I can find them with the search to:"Undisclosed recipients". Note the quotes.
> 
> The To: line in my case looks like:
> 
> To: undisclosed-recipients:;

RFC822 group syntax!  Fascinating.  You're right that notmuch doesn't
index group names, though I think it could with a small addition to
_index_address_group.  It already descends into group addresses, it
just currently ignores the group name.

> And I'm not able to find it in any way. Maybe notmuch won't parse it as an
> email and so won't store the To header to the database?

I suspect it is indexing it.  The only thing notmuch requires is that
the message be at least slightly well-formed and have either a From,
Subject, or To header.  You can find the message's Message-ID header
and try a search like

  notmuch search id:<message-id>

> Any idea if there is a way to dump what notmuch knows about given email?

There's no easy way.  You can use Xapian's quest and delve tools to
find the document ID and get the term list of a message, but this is a
*very* low-level view of what notmuch knows.

> Thank you