I like how fast it works even with all my contacts in one place. It is really easy to use as well! The only thing that i dislike about this app is its price tag. There are other apps out there for less money but they lack so many features compared to what we get here at $20/yr (it's not an annual subscription). This makes sense since their business model was built around people who want everything available through email so having things without paying extra costs is important to them too. We have been able to keep track of our employees' emails easily by just using MailO instead of switching to Gmail or Outlook every time someone changes jobs. They also make sure no spam gets into your inboxes if needed. Also has good security measures against hacking attempts.