Cyrus IMAP - sync two servers (one Public, one Private)

[Charles Marcus]

Hi Henrique (and anyone else who understands Murder),

Let me rephrase what I am trying to accomplish. Maybe Murder isn't the 
way to go...

1. I have a small, internal LAN that I want to keep protected, by 
blocking all unsolicited traffic (block all incoming ports to protect 
from port scanners/sniffers/hackers/worms). This LAN will contain a 
Private File/Mail Server running SuSE SLES9 - Postfix and Cyrus. All 
email access for our company is through IMAP - we haven't used or 
allowed POP access for a long time, and our Reps love having access to 
all of their email from anywhere.

2. We will also, for the first time, be bringing our Web and Email 
hosting in house, so we will have a second, Public Web/Mail server also 
running on SuSE SLES9 (Postfix/Cyrus).

3. In our business, we deal with a lot of binary attachments (jpegs and 
PDFs mostly, some fairly big), so, for performance reasons (I want our 
email sessions, which up to now have been slow - sometimes 
*excruciatingly* slow - to be very fast), when employees are physically 
in the office, I want them to only talk to the internal, Private IMAP 
server over the gigabit switch (ie, not have to have 30+ employee IMAP 
sessions all jammed through a single, 10/100 firewall port to talk to 
the Public IMAP server).

4. For Security purposes, whem employees are physically *outside* the 
office (accessing from the internet), I want them to only talk to the 
Public Mail/IMAP server.

So, to summarize, we will have two Cyrus IMAP servers, one Public, one 
Private. Most employee access will be from the internal, office LAN, but 
with occasional access from the internet (home, vacation, etc), so the 
Mailboxes on both servers must be kept in sync. Short delays (up to a 
few minutes) in the sync process are acceptable.

What is the best way to accomplish this?

Many thanks for suggestions,

Charles
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