 Sorted!
Fixed!
I've traced this to what I believe to be a problem with the iphone. When the phone moves between a public and private DNS server, which is what happens when it's on the LAN Wifi and getting local DNS from that, and public DNS from the cellular network; it all goes wrong. The phone, like OSX caches the DNS results and it seems to be this that causes the problem.
I've worked around this by changing the server entry on the phone from the DNS name of the Zimbra server to it's public IP address. Setting it to the address means it does not change. This works fine from outside of the lan of course, but you may need to change a setting on the firewall if applicable, to ensure that the port-forwarding, if used, is functional from inside the firewall.
This can be tested by trying to access your zimbra server from a browser using your external IP address, if it works, then you are good to go.
That's what I've done, and push now works perfectly. |