Life is full of adventures, sometimes you move to a new home, sometimes you head off on a long journey. Wherever you go, your postcards should be able to find you! That is why it is important to keep your mailing address up to date in your profile. You can change it anytime, as often as you like.
If you do not know your new address yet, no worries! Just leave the field empty and the site will simply skip you as a possible recipient until you are ready to add it again. A little tip: better to update or remove your old address about a month before you leave. That way, most of the postcards already on their way will still reach you safe and sound.