https://www.bleepingcomputer.com/news/microsoft/microsoft-disposable-emails-now-available-in-exchange-online/ > Microsoft says that Office 365 customers can use unlimited disposable recipient email addresses after the Plus Addressing feature rolled out to all Exchange Online users. > Plus addressing (also known as subaddressing or detailed addressing) allows users to create an indefinite number of custom and unique email addresses by adding suffix text strings to their standard address using a '+' delimiter.