I have never had any problems with most smartphones with our email server. The droid eris will not work correctly with smtp. We use smtp authentication when not in the network and it will not work with the droid eris at all. We usually use tls on port 25 for smtp but it doesn't work. It pops up a bad certificate and says our cert is incorrect. Has anyone been able to get an android 1.5 device to work with zimbra correctly?