It is in fact German and Greek:
The first half "German" probably says something like
"Hey,
I found this old post card, it belonged to a family member who has long ago passed away. The post card is very very old and brittle. Rather than risk it's destruction by sending it to you, i was wondering if you could translate it for me as i cannot understand what it says and i am quite curious. The post card reads:"
then the Greek part starts, which ironically says:
"Hey,
I found an old letter, it belonged to my grandfather who has died many years ago. I have enclosed the letter in this envelope in the hopes that you could translate it for me. Thank you for your prompt attention on this matter."
and thus begins a long chain of mystery
LOL
Ok i'll leave now