When sending international mail, the last address line must contain ONLY the destination country - no other details may appear on that line. You did not place the word "Canada" as the last row.
The correct address should look like (using a fake address):
MS HELEN SAUNDERS
1010 CLEAR STREET
OTTAWA ON K1A 0B1
CANADA
In case your user's country settings (Control Panel > User Settings > General > Country) are set to "Canada", we assume you're sending the letter to your country and so we add the country name if it does not appear on the last line.
We currently only validate US addresses.
When sending international mail, the last address line must contain ONLY the destination country - no other details may appear on that line. You did not place the word "Canada" as the last row.
The correct address should look like (using a fake address):
MS HELEN SAUNDERS
1010 CLEAR STREET
OTTAWA ON K1A 0B1
CANADA
In case your user's country settings (Control Panel > User Settings > General > Country) are set to "Canada", we assume you're sending the letter to your country and so we add the country name if it does not appear on the last line.
Please read how PostalMethods handles postal addresses for more.