Outlook bouncing back emails from senders

Hi, we are a small business, that pays for the hotmail live plus yearly. We are not being able to receive emails today. It has happened previously as well. The senders tell us that they bounce back. I've been on the phone for hours trying to get assistance, but finally they said there's no team to assist over the phone, then tried the chat, still no help, finally trying the community forum. Please help, as our work is mainly done through email.

Looking forward to a solution

Thank you!