It's a fair sized PO (three counter slots) at the back of the newsagents in a town of around 15k population. I was told at the time of the split that there was some 'bad blood' between the two parts and RM refused to collect from the PO. The post box went straight away (and hasn't returned) and the PO staff had to take their parcels and letters over to the RM depot (about 150m away but across two roads).
Things calmed down and RM now collect parcels but there's no letter box in the PO. The counter staff will take letters if you ask but it's done as a favour (as I've been told on several occasions). If they don't offer (they have a huge staff turnover and the new ones often forget) you have to go to the RM depot with them. It's not a huge issue but it still involves an extra journey. As I mentioned it's not uncommon to see people who don't know the 'system' - they buy stamps without putting them on the letters at the counter - wandering around looking for the box.