Swedavia at Umea Airport sent me a confirmation having received my reception report of NDB WU-329 and VNA-364. I am afraid that I can’t actually call this one a QSL… it is more a “thank you” and polite referral to LFV “Luftfartsverket”. LFV is the organization that remotely operates 16 airports from four control centres in Sweden: ATCC Stockholm, ATCC Malmö, RTC Stockholm and Östgöta Kontrollcentral (ÖKC).
With 1566 and 1578 kilometers from my home QTH these rank pretty high in terms of distance.