"Cannot find -lcrypto" message when compile fetchmail

Hi,

I am a newbie to linux and fetchmail.
I have just downloaded the Tarball, "fetchmail-5.6.0.tar.gz" and trying to 
install it on my Redhat Linux 6.1
I log in as a root, and execute "tar xzf fetchmail-5.6.0.tar.gz" and a 
"fetchmail-5.6.0" folder and files are unzip from it.
Next, I follow the "install" document to use the "./configure", everything 
works fine.

Then, I use "make" command which process a while. At the end of the process, it 
stated:
/usr/bin/ld: cannot find -lcrypto
collect2: ld returned 1 exit status
make: *** [fetchmail] Error 1

Pls advice.

Best Regards,
Clarence Lim