You can go back by following this thread:
remove/disable imapproxy
In essence, what you want to do is disable the service from starting and change the IMAP ports to listen on the standard ones. If you have a firewall handling NAT in front of your Zimbra server, you can also just forward up to the actual IMAP ports for now, bypassing the proxy until you can get it fixed.
You can find the ports via:
Code:
zmprov gs host.zimbra.com | grep Imap
to find the bind ports and use something like:
Code:
zmprov ms host.zimbra.com zimbraImapBindPort 143
zmprov ms host.zimbra.com zimbraImapSSLBindPort 443
Be sure to modify your ImapProxy bind ports the same way so they don't conflict.