Hi,
As per checking from the error message you encountered, this is due you've reached a sending limit or quota associated with the account. One of the factors resulting to this error is when sending messages to a large number of recipients, even for legitimate purposes such as newsletters or announcements for an organization.
At this time, you may try to reduce the number of recipients per message, or wait for 24 hours and trying again.
Additionally, please note that Microsoft does not provide a way for users to manually increase sending quotas on personal Outlook.com accounts. If the account has been temporarily restricted due to volume limits, the restriction is typically lifted automatically after some time, provided the account continues to be used normally.