Error with comment and calendar

Hi,

I'm a new french teams user.

Daily i use planner to organize our software development task. It's great!

But i can't send a new comment in a task, error : "You don't have access to..."

Unfortunately i can't use calendar too. "Sorry... We dont't find you mailbox..."

I have an office365 account and an external exchange account. I don't find where i can set my exchange in my office to see it in Teams.

I dont't know if there is a link with my comment problem.

Please help me to configure that.

Regards.