time
i've done this twice. Once approximately 4 weeks ago and they post a few days back. I sent the boarding pass by standard mail, 2nd class. The first time, it also took a similar amount of time - about 4 weeks, i sent that by recorded mail, signed for just in case.
I think they will post, but expect a 4 week processing period (no more, no less) from what i've seen. Now if ur posting from the states, expect 6 weeks just in case.