I usually use Transfer Wise or Paysera for making quick transfers around Europe. The latter may be better in case you want to make a transfer to Poland. Depending on the bank it is possible to make a transfer for up to 1.50 PLN. To some banks it can be made for free. However, first you need to set up an account and there also is a small fee for depositing this account. Though in the end it is one of the cheapest options, to my knowledge. It takes up to 3 business days.