I haven't used dovecot proxy or director. If I have a setup where all my users are connecting to HOSTNAMEOLD, is it possible to have 1 imap user that is connecting to HOSTNAMEOLD directed/forwarded to HOSTNAMENEW? Without changing my dns settings and preferably without creating any new servers. I think I can route one users mail to HOSTNAMENEW with sendmail ldap routing. So the only thing I need to be able to do is have the incoming imap requests on HOSTNAMEOLD been handled by HOSTNAMENEW.

HOSTNAMEOLD          HOSTNAMENEW      
                                      

+--------------+ +--------------+
| SENDMAIL | | SENDMAIL |
| | | | | |
| | | | V |
| V | |--------------|
|--------------| | lmtp |
| NS /INBOX | | | |
| mbox on | | V |
| block device | |--------------|
| | | NS /INBOX |
|--------------| | mdbox on |
| NS /ARCHIVE | | block device |
| mdbox on | | |
| clustered fs | |--------------|
| | | NS /ARCHIVE |
+--------------+ | mdbox on |
| clustered fs |
| |
+--------------+