Microsoft will provide Office 365 customers with support for using disposable email addresses to make it easier to manage their inboxes and to keep track of email campaigns. The new feature is known as plus addressing (subaddressing or detailed addressing) and it works by allowing Office 365 users to create an unlimited number of custom email addresses by adding suffix text strings to their standard address using a ‘+’ delimiter. Microsoft also added support to Outlook on the web browser-based client for sending emails using alias email addresses in December 2019.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-office-365-will-add-support-for-disposable-emails/