You can generate one-time-use email addresses by using the little-know mailbox field of the email address format:

kepix+you_can_write_anything_here_and_it_will_reach_your_inbox@gmail.com

Obviously this will not fool a human being into thinking you are a different person, but I have never encountered authentication code that two mailboxes at the same address to be the same person. This is useful for identifying the source of data breaches, when you start getting phishing attacks at your “kepix+reddit.com@gmail.com” address, and makes it trivial to train your spam/important filters.