In this how-to, we'll describe how to compile a new version of th exim src.rpm file in order to update exim. We'll use exim 4.69 for the example, so if you need a new/older version, just replace all instances of that version with the version you want (assuming we have it on our server).
wget http://files.directadmin.com/services/da_exim-4.69-2.src.rpm rpmbuild --rebuild --force da_exim-4.69-2.src.rpm rpm -Uvh /usr/src/redhat/RPMS/i386/da_exim-4.69-2.i386.rpm /sbin/service exim restart