If a package from USA to Canada gets seized, that's pretty sad. Up your damn stealth and maybe this won't happen to your future international customers. I've ordered dozens of times from the states, a different address, and the first time I order internationally from this one it gets seized. Now to await the love letter.
I've never even tried MXE, and I've been here for all the bullshit surrounding RCI, but I highly doubt you would immediately know if your package was seized.
I have no interest in the matter, but I'm willing to bet your package is just taking a while. Be patient man.