FedEx COD is super, BUT don't expect them to check the authenticity of the cashiers check or certified check they collect for you (I don't think they take money orders, or in any case check only the "cashier/certified" box)
It is up to you to do your due diligence and get a fax or scan of the check from the buyer. Get the issuing branch phone no. from the buyer also, it's not always on the check. Call the issuing bank to verify before your item is delivered to the buyer, and the check collected for you by FedEx. You can always call FedEx and ask them not to release the item if you suspect a counterfeit check.
It is up to you to do your due diligence and get a fax or scan of the check from the buyer. Get the issuing branch phone no. from the buyer also, it's not always on the check. Call the issuing bank to verify before your item is delivered to the buyer, and the check collected for you by FedEx. You can always call FedEx and ask them not to release the item if you suspect a counterfeit check.