How to split on content-length?

[Tom Koelman <tkoelman@xs4all.nl>]

Hi,

I am using regular splitting to sort my mail in a lot of groups. Now I
would like to add a group containing all the "big" mails, with big
being defined as, say, bigger than 140k (Swen anyone?). I guess I
should write a function now to do that, because I don't think I can
use a regular expression to express that I want to split if
X-Content-Length: is followed by a number bigger dan 143360, but I
don't understand the doc. It says:

      The second element can also be a function.  In that case, it
      will be called narrowed to the headers with the first element of
      the rule as the argument.  It should return a non-`nil' value if
      it thinks that the mail belongs in that group.

Does this mean the second argument will contain the headers?

Tom