Europa Stamps on Postcards.

Hello:
I'm worried because I recently sent five postcards to Russia, most of them with this year's European Post (CEPT) stamp from Spain. There's one for Turkey and another for Germany. They haven't arrived yet, which makes me think there might be a "postman" who collects stamps, or that for some reason they're not allowing letters with this stamp into Russia. Are you experiencing the same thing? Two of these postcards have already expired, and the others are about to. I don't know what to think.

@ Teideman, Russia is one of the "difficult" destinations, but they arrive within a couple of months at most.
One of the users replied to me a couple of times that he had problems reconnecting due to their international restrictions; therefore, he was unable to register them in a timely manner.
Ciao !