For some reason, my users started complaining that new mail wasnt showing immediately in their inbox. I've finally figured out why.. they are connected to the external ip address for the post office. I remember opening port 1677 for caching mode and setting the external ip address setting via C1.

Now, how or why the internal clients started doing that is beyond me. I made sure to set ngwnameserver to the internal address of the new post office (just made this change, it was set to the old post office (which still exists, but no users)).

Is that enough to fix the problem? or will the clients on the individual machines remember their last successful connection and keep connecting via the external address until I find them and force them to use the internal one?

Also, is there a way to prevent this in the future, while keeping the ability for offsite caching?