[horde] Problems with IMAP

[Mark Gardner]

I Know this is a little off-topic but you've all be so helpful in the
past.  I'm trying to get horde [cvs HEAD] setup on my RedHat 9  Box.
I'm trying to install php by compiling from source the version is
php-4.3.2  but when I try to do the ./configure -with-imap I get this
error:
checking for iconv support... no
checking for IMAP support... yes
checking for pam_start in -lpam... yes
checking for crypt in -lcrypt... (cached) yes
configure: error: Cannot find rfc822.h. Please check your IMAP
installation.
 
Any help would be great.
My current working Imap server is dovecot-0.99.8.1-1.dag.rh90 installed
via rpm
 
Thank You
Mark Gardner