Mail, no matter what it is, can take a while (~2 months) to reach Mongolia. Some may never arrive. If you are sending anything in a package, emphasize non-luxury items on the customs declaration, and don’t write down if it includes food! Envelopes under 4 pounds are usually not checked. It’s also a good idea to include the word “Airmail” on envelopes and use basic stamps (nothing fancy/too colorful).
Contact me at firstname.lastname@example.org for my permanent address!