The ability to create email aliases whenever you like by adding
a special character and some text after your username in your
email address. Ex. myusername-text@eng.ufl.edu. Any email sent
to this different address will still be delivered to your
regular email account.
Expansion addresses can help with filtering your message into
different mailboxes. They also help with dealing with spam, now
you can register to a website with an expansion address and if
you start getting spam to that expansion address you can have it
blacklisted.