Office 365 "Reached my 24 hour limit"

If you get "Reached my 24 hour limit" on your Exchange Online in Office 365 you probably reached the sending limit for cloud-based e-mail accounts.

This limit defines the maximum number of recipients that can receive e-mail messages sent from a single cloud-based account in a 24-hour period. The recipient rate limit for Exchange Online Plan P is 500 recipients per day, for E is 1500 recipients  per day.

You can take a look at help.outlook.com/.../ff381292.aspx about the detail and walk-around solution.