procmail distribution - gunzip problem

Hi,
        I am trying to install procmail on my machine
which is a Sun ultra-2 running Solaris 2.5.1. I got
the file procmail-3.11pre7.tar.gz from the main 
distribution site. But when I gunzip (version 1.2.4),
I get the message:

procmail-3..11pre7.tar.gz: not in gzip format

I tried several mirror sites and got the same problem.

I would be grateful for suggrestions.

-Prabhanjan