Last I checked the USPS is more than happy to deliver your E-6 to Dwayne's for a small fee. I would assume Canada Post would do the same. Fuji pre-paid mailers for E-6 can be bought from B&H with Dwayne's address on them.
But, you say, it takes two weeks to get slides back from processing if it's not done locally. Big deal! 20 years ago it took two weeks to get slides back from send-out processing. The wait gives me more time to forget what was on the roll, and when I get it back and toss 'em in the projector, I get to see 36 never-before seen images (no chimping!). It's like being a kid again on Christmas morning!
ME Super, aka The Slide Curmudgeon