Thanks Charlie. I hope that you are surviving OK.
This was before the virus was an issue. The delays might have been related to the approaching Spring Festival. However, it seems as if China Post have gone all pedantic on us as they appear to have new guidelines. Needless to say the guidelines are not necessarily relevant for the UK but failing to follow the guidelines can result in them refusing to accept mail despatches. We ended up using a courier to despatch a simple letter.
I am currently back in the UK scanning the internet for the indications that it is OK to return. Meanwhile we are relying on couriers for important mail since there is every likelyhood that there are going to be massive backlogs on mail deliveries within China for some time.