Notmuch indexing 21 million emails

[Tom Bulli]

I have a project where I need to search about 21 emails - and decided to use "notmuch" for it.  The system is a Debian Squeeze, the notmuch version is "0.8-1~bpo60+1" from "kyria's" private repository.

I am running the "notmuch new" for approx. 4 days now - and according to "not,uch count" it has indexed about 4.5 million emails.

Is this expected performance?  Is there any way to speed that up?