Super appli,… jolie interface, mais attention, la partie calendrier plante … en ce jour du 29 février 2016 !!!
J’ai modifié la date système à celle d’hier (28/02/2016) et ça tourne impeccable …
Donc si vous avez les memes problèmes dites moi et attendez demain 1er mars pour vous servir du calendrier em client 
Perform the following steps.
Exit eM.
Set your system date to February 28.
Start eM.
GO to Calendar and select ANY view except Month view. I prefer Week view.
GO back to mail.
Exit eM.
Reset system date to February 29.
Start eM.
Everything should work but do NOT go to Month view. It will immediately experience an application error.
FYI, if you are running v6 there is an official fix for the issue. My steps above will temporarily resolve the issue for both v6 and v7.
Hope this helps.