I have a few friends on missions, and I decided its about time I be a good friend and write a couple. How do I use the pouch service? How many stamps should I use if the letter will go to foreign countries? Does the pouch service work for all countries in which missions are served? Spain? Philippines? Peru? Does the pouch service work for all of those? Basically, any info you have on the pouch service I would love to hear. Thank you! -olivia.