We're running ZCS NE in a cluster and ran into a weird problem this morning. Our users could not get logged in. They could connect to node A, but if there account was on node B it wouldn't redirect their connection...or it would try and then throw an error up in the log saying it couldn't proxy over.
We finally tracked it down to the zimbraMailMode being set to 'http' instead of 'mixed'. We have had it set to 'mixed' mode since it's been setup, and as far as we know, no one has done anything that would have set it back to 'http'.
So now the mystery is...how would zimbraMailMode have been set back to 'http' automatically? Is this a possible bug? Are there instances where the server might set it's zimbraMailMode to a default?