Sender Address Different Than Specified

NOTE: I have already submitted this to SendGrid ticket support, and after trouble shooting with them I was told to submit a post over here. The ticker number was: #1306956

I am using the SendGrid plugin for my wordpress site, in the plugin I specified a certain sender address but when someone uses our “contact us” form the email I receive is from the email address specified in my wordpress settings in the general page and not from the one set in the sendgrid pluign. The email does say it was via sendgrid.net so it is working. How can I have the sender address match the one I set it to be in the plugin?