You can send your cards direct to the foreign bureaus. Any one can do this without membership in any society such as the ARRL. Addresses are listed here:http://www.iaru.org/iaruqsl.html
For example, if you have 10 cards to send to Germany, instead of mailing each one direct to the recipient, mail the batch of 10 to the German bureau.
Although only ARRL members can use the outgoing ARRL bureau, all US hams can receive cards via the ARRL bureau.