You should make sure that the "Approved Sender" address in your Feedback Genius "Connected Marketplaces" box matches either the email address that you use to log in to Seller Central, or is listed as an "Alternate Address" here.
(If the link does not redirect properly, or you are trying to access Seller Central for a different Amazon marketplace, simply login to your Seller Central and click on Messages (top right). From the Tools and Resources section, click on Alternate Address.)
The "Approved Sender" is the e-mail address that FeedbackGenius will send messages from. Please note that this is NOT an email address that buyers will see. When messages are sent through Amazon's Buyer-Seller Messaging system, it rewrites the message to include your Amazon store name and a cryptic looking email address i.e. firstname.lastname@example.org.
To add or update a new "Approved Sender" within Feedback Genius, click your email address in the upper right corner tool bar menu and select "Settings" from the drop down menu. From the left sidebar, select "Marketplace Settings." Click the "Edit" button next to each Marketplace email to enter the desired email address and click "Save" to apply your changes.