If you provided a customs # that should be proof of mailing as it is scanned in by the USPS and any I have tried could be tracked til they left the US.Last knife I sent to Canada I could track until it left the US in Miami.
This is the info from a customs tag I mailed today.
First-Class Mail International
Dispatched to Sort Facility
March 12, 2012, 5:02 pm
HARRIMAN, TN 37748
International Letter
Acceptance
March 12, 2012, 12:15 pm
HARRIMAN, TN 37748
Also just tried some older ones I had but they are no longer in the system.
This is a knife going to Canada that is still in the system,I know it was delivered but see how the info stops when it leaves the US.Canada Post never showed the number at all in their system.
First-Class Mail International
Processed through USPS Sort Facility
February 18, 2012, 9:19 am
MIAMI, FL 33112
International Letter
Processed through USPS Sort Facility
February 17, 2012, 2:38 am
OPA LOCKA, FL 33054
Depart USPS Sort Facility
February 09, 2012
KNOXVILLE, TN 37950
Processed at USPS Origin Sort Facility
February 09, 2012, 7:45 pm
KNOXVILLE, TN 37950
Dispatched to Sort Facility
February 09, 2012, 5:07 pm
HARRIMAN, TN 37748
Acceptance
February 09, 2012, 11:32 am
HARRIMAN, TN 37748