Utterly pathetic at syncing or otherwise operating with any sort of hiccups in connectivity. This is a mobile app. Please design it with the assumption that it will be used outside, where cell tower handoffs happen and users will go back and forth between wifi and cellular service. Half the time, my email replies are not sent due to poor connectivity handling. I expect this poor level of fault tolerance from a small developer, not from a well funded team from Microsoft. Just plain shameful.