I had looked at sending E-wasted ~200lbs in December and I was going to send the packages off despite the shipping costs that ate into the profit margin. The following is the last e-mail they had sent me. I'm not sure if they worked any of these issues out, as I've since decided to keep stacking boxes of prepared mobo's in the shed until I have an EDI-size lot.

"I am having difficulty with the program to create labels for an international shipment. It will not allow me to change the schedule a pickup address to Canada. If you want to drop the items off at Fedex, I may be able to get past that. The other issue I was having was that I need to know the contents of the boxes in order to generate the customs paperwork. I tried to enter a generic electronic parts, but it wants a more specific description. In the interest of time, you may want to investigate the international flat rate boxes. Since this is a prompt & respond program, I don't know what else I may encounter that may require more information from you. I may have to discuss with my manager if we are going to accept international shipments under the label program due to the information required to complete the customs forms. You will probably have to go thru a similar process with the post office for the flat rate boxes as well. Let me know if you still want to proceed."
*Edited to add quotation marks to e-mail text for clarity*