Excluding offers that don't come through GSA Ebuy for GSA RFQs?

I posted an RFQ on GSA Ebuy. However, one vendor decided to send the offer through email instead of through the GSA Ebuy system like every other vendor.

I didn't think I had to actually specify all offers have to come through GSA Ebuy because I thought it would be obvious.

Can I (or do I have to) exclude this offer that didn't follow the correct procedures to send the offer via GSA Ebuy?

Edit: Please delete this topic, as I believe this is more appropriate under the Beginners section.