Microsoft adds support for custom email addresses to Office 365 services, a feature that hopes to be completed in the third quarter of 2020.
Custom email addresses are an option that some email providers may support. The feature is described in RFC 5233 internet standard ..
It is known as a secondary address. This template allows users to extend their email address using the "tags" or plus (+) character.
The "tag" can be unique each time, allowing users to create an infinite number of custom email addresses, which they can add to shopping companies, newsletter subscription forms, contact forms and other online forms.
Once the emails reach the user's inbox, the owner can see which email address the sender used.
Note that this function already exists in gmail of Google.