I am troubleshooting inconsistent IMAP functionality in multiserver installation, and wanted to find out, where does Zimbra Proxy get IP address for exact mailbox server. We deploy multiserver environment and split DNS. Mailbox server on mailbox, LDAP and Proxy resolve to DMZ IP address, but nginx.log displays upstream IP address, which is NATted. The connections go through, but can not find resource, where NGINX gets this IP. Have to troubleshoot firewall too.