Unwanted Items Sent to My Mailbox

Our system is set up such that every card that arrives addressed to your COMC Mailbox must be processed, unless any "filler" cards are found clearly marked upon the package being opened.

How do I let a sender know to not send me extra cards?

Here is an example of what to say to your sellers: 

“This order is being sent to my COMC Mailbox, and I am charged a per-item fee. Please do not include bonus or filler cards in this shipment. If you use extra cards as spacers or packing materials, please mark them with a large 'X' so that they are not processed.”