I just installed the Rawhide package on my CentOS 5 system. The one item that bit me is that the config file defaults to using interface "[::]" so it only listens on IPv6. (This is from a patch in the package that changes the upstream default of "*", so it only affects those using the Fedora package.)
For those wanting to track the issue, here's the Bugzilla:
<https://bugzilla.redhat.com/show_bug.cgi?id=453054>
I rebuilt the package from the source RPM, to make sure it was "tuned" to the C5 distro.
I got the source RPM here, from the Portland State mirror:
<http://mirrors.cat.pdx.edu/fedora/linux/development/source/SRPMS/dovecot-1.1.1-1.fc10.src.rpm>
Here's a full list of Rawhide mirrors:
<http://mirrors.fedoraproject.org/publiclist/Fedora/development/>
If you'd like to see all Red Hat bugs associated with dovecot, here's a suitable query: