Standard delivery to Portugal (taking 10 to 13 days) costs €8 for orders under €60 but is free for orders of higher value. (Only clothing and home products can be delivered overseas):
https://www.marksandspencer.com/c/help/international
I have it delivered to a transport company in the UK. Forward the invoice to them by email. They clear customs for the entire lorry load then I pick up from their depot in the Algarve