Don't know if it is similar for the whole of Europe, but for West Europe it is 98 cents by airmail.
postcard are still used widely. Postcards take a long time to reach.
The time it takes to send a postcard to its destination can vary depending on the distance and the postal service used. Typically, it can take anywhere from a few days to a few weeks for a postcard to reach its destination.
The current rate to send a postcard is 33 cents. The postcard must be no longer than 6 inches long by 4.25 inches high and .016 inch thick. If it is bigger or thicker, it requires additional postage.
It depends where exactly you want to send it. Better ask at the post office. I pay 90 cents from NY to Eastern Europe.
around 3 to 5 days
To send a postcard or greeting card from Australia to Japan the airmail price is $1.60.
dont send them
PostkarteorAnsichtskarte
It depends on where you send it from.
USPS.com says it costs 98 cents to send a postcard from the US to Australia.
A postcard is a thing - a message card you send in the mail. All "things" are nouns. Postcard is a noun.