They will just accept post that you want to send. Not much advise available on how best to send. I had to pay 100 pounds as penalty due to missed inputs while sending. As this is just a shop outlet, I can't question them as well. So prepare yourself with all inputs required to send.Edit: I sent email to DHL reviews as mentioned... read full comment
From DHL Express Service Point (WHSmith Stratford Maybird)
DHL Express offers a fast, secure, and reliable worldwide courier service from over 1,300 DHL Service Point locations nationwide – conveniently situated at your local high street or retail park near you. Send letters or parcels within the UK or internationally to over 220 countries and territories with DHL, the global leader in international shipping. Free envelopes and boxes are provided in store. Simply choose the box size you require, pack and pay in store. Pricing is based on the size of the packaging and the zone that you’re sending it to – no weighing, measuring or printing is required! Reduced CO2 emissions across our network with any parcel sent internationally from a DHL Service Point by the purchase of Sustainable Aviation Fuel.