Gmail supports plus-addressing, affording you some rather powerful email-handling, routing, and filtering functionality.
eg. if your email address is firstname.lastname@example.org you can use plus addressing as email@example.com
and go on as firstname.lastname@example.org
So you can make up an unlimited number of arbitrary email addresses to use when signing up for something, making a purchase online, or tracking a conversation and mailing lists.
Set up a filter check