Sign in to your Binghamton University email - http://bmail.binghamton.edu
Click the Settings icon in the upper-right and select and select See all settings
Under the Accounts Tab look for "Send mail as"
Click Add another email address.
In the Email address field, enter your name and alternate email address [Alias]@binghamton.edu
Keep the box for "Treat as an alias" checked.
Click Next Step.
The alias address should be added. To make it the default sending address, click "Make Default".