I have had several inquiries about how Covid-19 affects the delivery of your QSL cards. It is a fluid situation and after taking advice from Royal Mail i can inform you that posting from the UK is continuing as normal.
Nearly all mail is sorted by machine so is not touched by human hands. Large mailings are bagged from here and sent directly to London Heathrow Distribution Centre and the bags put on onward flights to the destination country.
Royal Mail has a page on the website updated for “International Incident Bulletins” this link will take you to the page so that you can see what restrictions are IN YOUR OWN COUNTRY and where delays may apply or indeed occur.