Using classic Outlook for Windows in business environments
Hello, My name is Sajjad and I will be assisting you.
I understand your concern. Just so there is no misunderstanding, this is a public user-to-user support forum. We're users just like you helping other users. We do not work for Microsoft and have no access to any user account so there is nothing we can do or check from within the forum.
I would suggest checking your Outlook Storage again in OneDrive in the link below to see if you have enough space to send or receive emails:
https://outlook.live.com/mail/0/options/general...
Starting February 1, 2023 cloud storage used across Microsoft 365 apps and services will include Outlook.com attachments data and OneDrive data. For storage, your emails will be stored in the 15 GB of storage that is provided by Outlook, and any attachments will be saved to OneDrive 5 GB. If OneDrive storage exceeds the limit, you won't be able to send and receive messages through your email account.
To learn more please refer to this link:
https://support.microsoft.com/en-us/office/chan...
On the other hand, have you tried it on other web browsers or devices? Were they the same?
In the meantime, you can also check this article which is related to your problem:
https://support.microsoft.com/en-us/office/can-...
Warm Regards,
Sajjad
Note: This is a user-to-user support forum and I am a fellow user.