Sending, receiving, and organizing email in Outlook.com
Hello,
This is a temporary Outlook sending protection limit, not a permanent block.
Microsoft explains that Outlook may temporarily restrict sending if the system detects unusual sending patterns or spam-like activity, even if you did nothing wrong.
Official info: https://support.microsoft.com/en-us/office/sending-limits-in-outlook-com-279ee200-594c-40f0-9ec8-bb6af7735c2e
What you can do:
Stop sending emails for 24–48 hours
Check login activity: https://account.live.com/activity
Change password if anything looks unusual
In most cases, the limit is automatically removed after a short time.