I like how well it integrates my office 365 account, so from one place i can control all of our emails for each person in every department across multiple locations at once! And if something needs changed or updated quickly after that happens there is no lag time between changes being applied immediately online vs waiting until someone logs off/back onto their computer later when they're away form workstation etc..
This has been an asset since we have moved over 100 people out of using Outlook mail (which was terrible) now everyone uses this instead which makes working together more efficient as things are posted up within minutes rather than hours sometimes days even!! We've also noticed some issues regarding getting messages sent via other programs such as outlook desktop notifications but not sure yet what exactly those might be? Other then these two minor problems everything else works great otherwise :).