Life / Sending small parcel from Poland to other EU country question [3]

Hi Everyone!

Is it possible to post a envelope / post bag like this in an ordinary Polish letterbox with just stamps according to weight ?
Is there any any rules that you need sender address and sign when received in another EU country?

transpack.co.uk/media/catalog/product/cache/1/small_image/295x295/9df78eab33525d08d6e5fb8d27136e95/_/q/_q0v5953copy.jpg

Hope you understand my question ! :)
Read alot about involving Post office in Poland but is it needed ?

Travel / Warsaw meet escort girls [5]

I've been looking around alot on google about Poland / Warsaw and the amount of escort girls is like nothing I've seen befor :)

Do you ppl have any tips or input what to think about befor meeting a escort girl ?
Can a Polish cellphone number help in order to get in touch with the girls ?

There is a few listed brothel's / gentlemen club's on google, website's and contact info seem's old in many cases outdated.
Is there any recommended club to visit ?