Unable to download mail from my alice.it account

For days now this mesage continues to appear after attempting to download emails onto my Windows Live Mail (2012 version for Windows XP)

"Unable to send or receive messages for the Alice (lalunanelpiatto) account. Header download for the 'Inbox' folder did not complete.

Server Response: Your IMAP command could not be sent to the server, due to non-network errors. This could, for example, indicate a lack of memory on your system.
Server: 'in.alice.it'
Windows Live Mail Error ID: 0x800CCC0F
Protocol: IMAP
Port: 143
Secure(SSL): No"

I have 3 email accounts, 2 with Tiscali which are working fine, this is the one always giving me problems (from the start, anyway, not from when the error message has been appearing), for instance I am never able to move mail to the bin to delete it. I click delete and it stays forever in my inmail folder.

What can I do? I have not updated Outlook recently s I don't understand why. I haven't changed any settings either