No more reception and sending Outlook messages

Dear all, I work on Mac IOS Mojave and use Outlook 16.47. I often have problems like messages that I can delete definitely or messages that I received several times even if I've already deleted them.
But that's not why I'm contacting you. 
My big problem is that I can't send and receive messages anymore since yesterday 7pm.
I can send or receive them through gmail but not through outlook anymore.
Please help. I don't know anything regarding computers...
Thanks.