Windows Live Mail Error ID: 0x800CCC0F

I have been using Windows Live Mail for a couple of years, and it's been fine until now.  I cannot receive e-mails with attachments, but e-mails without attachments arrive OK.  It's happening on my tablet as well.  On Monday Windows Live Mail was working OK, then on Tuesday it wasn't, and I don't know how to fix it.  Nothing was changed overnight, but in the morning after shutting the computer down, I switched it back on and opened WLM, which said that it hadn't closed down properly.  I've checked all the settings for the e-mail accounts, and they're OK.  I've spoken with my ISP to check that they're not throttling bandwidth, and they're not.  Following on from checking with my ISP, I tried an alternative mail app on the same computer, and I can receive e-mails with attachments OK, so it's nothing to do with the ISP.  (The alternative mail app doesn't suit my needs though.)  I've tried going to web mail and sending from there to a different account in WLM, but I get the same error message in the other account.  I'd like to get Windows Live Mail back up and running.  This is the error message, and I hope there's someone who can help:

Thank you.