I'd definitely suggest taking a look at Meest UK. I've used them several times and the service has always been straightforward. They offer both air and ground delivery, depending on how quickly you need the parcel to arrive, and it's delivered right to the recipient's home. Before you book, you can even use their online calculator to check the shipping cost, which I found really useful. Their FAQ section also explains customs, insurance, and other practical details. Here's the page I used: https://uk.meest.com/services/international/delivery-to-poland/