Anyway, this morning I hunted around the WordPress interface looking for all the email setup fandango but there was nothing, just a notice saying that I could only get Google Apps with a paid account. Whatever that means.
The thing is that the email address with the custom URL is essential. For one thing it is the email address I used to log into WordPress in the first place. It predated my setting up the site on WordPress, so it has to work otherwise I won't be able to receive any communications from WordPress. The other thing I used it for is Twitter. It is the email address I used to set up the Twitter account for the new site.
You would think that WordPress would give users a whole bunch of configuration details, including a special page for configuring email addresses. But there is virtually nothing inside the interface to help you with this sort of problem.
Anyway, I got in touch with the ISP who I originally registered the URL with. They are also the ISP who I paid to set up a hosting package for the URL. They told me that the domain is being controlled by WordPress and they also said that I needed to give WordPress some "mx records", which they supplied to me. But as to where inside the WordPress interface you put these details? There's no guidance from WordPress.
Frankly this is a real annoyance. For people who want to use their own URLs, this email stink-up means that you need an advanced degree in computer science just to set up the interface correctly. I seem to remember a page full of stuff about email addresses when I first set up the site but that page doesn't show anywhere now, some months later. It's a complete downer. In frustration, I contacted an outfit who advertise online and who are based in Melbourne who say they are experts in setting up WordPress. I sent them a message, so we'll see what comes of that. There's no point in getting in touch with WordPress because you have to log in to the forums to get help, and I don't even know if the email address I used to log into WordPress in the first place is still viable!