Find the best Shipping partner for an e-commerce business dealing with oversized parcels within EU (Netherlands, Belgium, Polan)

I am looking for someone with experience in Shipping and logistics for online businesses. You will help us find the best and cheapest shipping methods to send parcels and shipments between The Netherlands, Poland, and Belgium. We sell items that vary in size and weight up to 70kg packages. You will help us find the best shipping companies to work with for shipping, returns, and handling of lost and damaged items.

Please contact me if you have the experience needed.