ok...another forum I'm on...folks share pollen fairly often.
first you need to dry it very well, low heat like under a heat lamp, full male flowers "just" ready to open or FRESH pollen. next it NEEDS to be kept dry, no water, it kills the pollen, and lowest humidity as possible. it should be packed with a desiccant and kept in fridge or freezer if to be kept for any length of time.
the usual routine is this, collect and dry pollen on a pane of glass or mirror( the more the better)take a small bit of rice and flour( as an extender and dryer) and dry them also, once its all dried to your satisfaction( no hard rule here and cooking pollen is BAD) pack it ALL in a sealed glass vial , then freeze or mail ASAP.
much of the pollen will not survive, so as much as can be gathered the better, but if you only need 100 or so seeds its VERY doable. it can be a bit hit or miss as Nev said. mailing Continent to Continent could be an issue, though I know folks that have done it with success.
you can keep pollen for 3-6 months no problem, up to a year plus with some good luck.