Simon's RPM Upgrade & Repo

[John Thomas]

This is a hobby for me.  I have a back up, but with my skills it would
take me a long time to restore so I am a bit worried and your guidance
is appreciated.

I am running Cent OS 4.3 with Cyrus 2.2.12 configured as suggested here:
http://www.delouw.ch/linux/Postfix-Cyrus-Web-cyradm-HOWTO/html/
except I have added the following to my imapd.conf:
   unixhierarchysep: yes
   duplicate_db: skiplist
   tlscache_db: skiplist

I would like to upgrade to Simon's RPM.  Is it safe to download his rpm
and run "yum update cyrus-imapd-2.3.3-6.src.rpm"?

Also, is there a repo that has stable Simon's rpms so I can
automatically stay updated with his rpms that have shown reasonable
stability.