Yikes. At ~60/u/mo for enterprise email & collaboration I would drop the "Replace Microsoft Outlook" line... unless you want people to start looking at what else they get beyond Outlook/Skype for Business from Microsoft for $20-$35/u/mo (E3 or E5 O365 license).
But Front won't be replacing anyone's free web mail at any price point. I can't believe they don't have a free plan.