If you are setup to send emails from another account but only see the option to send from your normal call federal email then follow the steps below.
Open a new email
Click the options tab
Click the ‘from’ button on the ribbon. This will make a ‘from’ drop down box to appear on your email
Click the ‘from’ drop down button on the email. Then click the ‘other e-mail address option.
Enter the email address that you have been set up to send from
Now when you go to send an email you will be able to choose which email you would like to send from