Sebastian Fischmeister <sfischme@uwaterloo.ca> writes:

> Hi,
>
> I'm trying out the internal expansion for notmuch-address-command. One
> thing I immediately notice is that it has lag over 250K emails, since
> it's lookup up addresses each time. Scripts like nottoomuch-addresses
> have cached results of only all email addresses and have instantaneous
> response.

There is caching with the internal completion, just not between emacs
sessions. So the second and following completions in a given session
should be much faster. I have almost twice that number of messages, and
the lag is barely noticable here. So maybe something's wrong if you're not
restarting emacs and still noticing completion lag.  You might have a
look at the variable "notmuch-address-completions". For me this has a
bout 3700 entries in it at a steady state.

> The second thing is that it seems to list any email it finds. However, I
> don't care about email addresses found in emails from 10 years ago. I
> only care about the last two years.
>

I think the plan was/is make this search customizable in various ways,
but so far nobody got around to it.