I am still running dovecot-1.2.17 on CentOS-5, I think the 2.0 and newer versions do get into trouble with selinux.
Recompiled within a local koji setup, based on newer RH rpms, so no atrpms version for me. Download from http://jur-linux.org/download/el-updates/5/
best regards,
Florian La Roche
I am running various machines (on CentOS 5.5 to 6.3,) with dovecot from 1.1.1 to 2.2beta1, the latter by compiling and installing into default /usr/local. All machines have selinux disabled :)!! Highly suggest reading http://wiki2.dovecot.org/Upgrading since there are gotchas for most upgrades that may or may not apply to your case.
Andreas Kassenides