Jean Louis, mutt user since 1999
Mutt is powerful. (Even though it has no nice website).
To know the power one need to learn.
Suites don't have time for learning. (And use Windows, ahhh.)
Give me few hours with any of them, and there will be efficiency demonstrated like they have never seen before. All by using mutt email client. Including any kind of calendaring, reminding, and so on.
P.S. Outlook is Windows thing, mutt is rather GNU/Linux and Unix-like thing and this is the main reason why™.
Contact GNU.Support now. There is a simple rule at GNU.Support: if we can help you, we do, whenever and wherever necessary, and it's the way we've been doing business since 2002, and the only way we know