If you are a student with an @mail.goucher.edu email address, forwarding is setup through the mail.goucher.edu web interface. Simply login to http://mail.goucher.edu, click Settings and then Forwarding and POP/IMAP. You will be able to set up your forwarding address on that page.
Tip: It’s a good idea to run a test to ensure your forwarding is working properly. Remember you essentially have two email addresses that go to the same inbox (email@example.com and firstname.lastname@example.org), so be sure to test messages sent to both addresses.