When you ask someone to email you using your Gmail account, you can ask them to use a plus sign and their initials (or whatever you want) right before the @ symbol in your email address. This does not give you a new email address. It is only an alias. You can use this for inbound emails only. For example, you would ask them to email you at your.name+test@gmail.com.

Organize Inbound Email

These aliases are handy because you can setup filters to put those messages into a label. To setup a filter, simply go to the search bar in your Gmail inbox, and type in the alias that you want to filter out. Click on the small down arrow on the right inside the small search bar. When you receive an email that has the alias, it goes to your main email account and it also goes to its own folder automatically. This way you can better organize your inbound emails.

Next you can create a new label before you create the new filter.

Now you can create a new label.

Now click the Create Filter button at the bottom.