[Dovecot] Another hint from the clue box 8-) imapc/imap proxy user mailbox server location

[Terry Carmen]

I'm running imapproxy as shown at  
http://wiki2.dovecot.org/HowTo/ImapcProxy. In fact, that's my config  
in the wiki. 8-)

It's been working, but has performance issues when the Exchange server  
that's hard-coded as imapc_host=xxx.xxx.xxx.xxx doesn't happen to be  
the user's home exchange server.

I'd like to point dovecot at the correct Exchange server based on an  
LDAP query, and in fact, have an LDAP search that works:

DC=example,DC=com

(&(objectCategory=person)(objectClass=user)(!(userAccountcontrol:1.2.840.113556.1.4.803:=2))(sAMAccountName=username))

With the exchange server being returned in the msExchHomeServerName  
property as:

/O=example/OU=INT/cn=Configuration/cn=Servers/cn=exchangeservername

I believe this should somehow end up in the userdb section, which  
currently contains "driver = prefetch", but can't seem to figure out  
specifically what should be there.

The only important part is "cn=exchangeservername", which is the  
machine name and would need to be prepended to example.com to get the  
fqdn.

Can anybody toss me a clue?

Once I get it working, I'll update the wiki.

Thanks!

Terry