Yah its fine I say its way more easier to get hash thru the mail rather than Herbs. The buds will smell something awful but the hash wont even come close to funking it up.
Canning works fine. I've had hash oil sent to me when i was living in Florida from the middle east. I had no problems with it getting to me. As long as the sender does a good job of canning it, but anything is possible.
Be very careful
