Yesterday I heard back from the Post Office about the P O Box number that I've applied for to use for this blog.
They wrote to tell me that my address isn't listed on their database and so, according to them, my house doesn't really exist. The irony of their writing to tell me this seemed to escape them.
I have now spoken with my local Council which has confirmed that my house really is where I thought it was. The Council has promised to tell the Post Office. And after that, I should get my P O Box number.
Until then, keep your fingers crossed.