Problem as it seems is the Corona crisis:
https://www.posti.fi/mzj3zpe8qb7p/7j...om-finland.pdf

But to be honest, as I have already written via pm. In my opinion it doesn't make sense to send it via another country, because transport gets far to expensive. From Germany a fully insured and trackable parcel to Greece costs 14€. Of course there are in principle some cheaper options, for example by sending it just with an insurance up to 50€. But I wouldn't do that. Being just an intermediary, I'd like to be on the save side.

I think the best option is to wait until your postal service serves Greece again, or to use another postal service.