multi server migration question/poblem.

[Gary Smith]

We have a client with about 500 accounts spread across 3 server.  These were office servers setup some time ago at the three different locations, running various different versions.

On server one, their user accounts are sjo_username (sjo being the city prefix).  
On server two, their user accounts are sfo_username (sfo being the city prefix).
On server three, their user accounts are username at domain.com

Server three is the destination for servers one and two.  All users now have usernames of username at domain.com.  We can directly map prefix_username to their new username at domain syntax without any problem

We would like to migrate all of the user accounts to the single server.  The server will be running cyrus-imapd.x86_64 v 2.3.14-1 (I just compiled it this week) on CentOS 5.3 (waiting to deploy still):
New server is currently running:
name       : Cyrus IMAPD
version    : v2.3.12p2-Fedora-RPM-2.3.12p2-3.HS 2008/04/24 16:09:27
vendor     : Project Cyrus
support-url: http://cyrusimap.web.cmu.edu
os         : Linux
os-version : 2.6.18-92.1.18.el5xen
environment: Built w/Cyrus SASL 2.1.22
             Running w/Cyrus SASL 2.1.22
             Built w/Sleepycat Software: Berkeley DB 4.3.29: (January  7, 2007)
             Running w/Sleepycat Software: Berkeley DB 4.3.29: (January  7, 2007)
             Built w/OpenSSL 0.9.8b 04 May 2006
             Running w/OpenSSL 0.9.8b 04 May 2006
             CMU Sieve 2.3
             TCP Wrappers
             NET-SNMP
             mmap = shared
             lock = fcntl
             nonblock = fcntl
             idle = poll


Old servers are running:
name       : Cyrus IMAPD
version    : v2.2.12-rPath-Linux-2.2.12 2005/02/14 16:43:51
vendor     : Project Cyrus
support-url: http://asg.web.cmu.edu/cyrus
os         : Linux
os-version : 2.6.18-92.1.22.el5xen
environment: Built w/Cyrus SASL 2.1.22
             Running w/Cyrus SASL 2.1.22
             Built w/Sleepycat Software: Berkeley DB 4.3.28: (October 23, 2005)
             Running w/Sleepycat Software: Berkeley DB 4.3.28: (October 23, 2005)
             Built w/OpenSSL 0.9.7f 22 Mar 2005
             Running w/OpenSSL 0.9.7f 22 Mar 2005
             CMU Sieve 2.2
             DRAC
             TCP Wrappers
             mmap = shared
             lock = fcntl
             nonblock = fcntl
             auth = unix
             idle = poll

I can place these machines side by side to migrate the email.  Question is, what's the best way to migrate the email while retaining the message flags and siege settings?

In the past I have tried replication but I have failed to get it working on the RPath distro and I don't really have time to troubleshoot the build problems on RPath.  I can however, setup an entirely new xen instance running CentOS 5.3 server and copy over the mailboxes to the new instance so at least they are on the save version.

Any suggestions on how to do this.  I'm attempted other ways in the past, but it's time to actually get it done and over with.

Gary