Email weirdness

[Simon]

I've been on the phone to a mate for the last half an hour, trying to sort out a strange email problem.  He's with IDNet and can receive emails on his phone using IMAP, but since 22nd Feb, hasn't been able to download emails onto his main computer via POP3.  The only recent change was his email password, which was also updated in his email client, and he has been able to send and receive emails since the change.  He can now send, but not receive, and for some reason, he cannot access http://webmail.idnet.com/ either.  That's not even the webpage, let alone being able to attempt logging in.

With his permission, obviously, I can access his webmail from my computer, and he can access every other website from his own computer, just not IDNet Webmail.

I have gone through his email settings, none of which have been changed form when they worked before, and seeing as this has affected two separate IDNet email accounts, I'm drawn to the conclusion that this is a local problem with his computer, but I can't work out what it could be. 

Any thoughts?

Edit:  I've just heard back form him that IMAP on his phone is now timing out, so there's definitely something weird going on.

[Steve]

IP address blocked which is a bit daft as it's one of IDNets. They do block some O2 and BT addresses as best they can already.

[Simon]

I did wonder that, Steve, but he can still log into his IDNet account.   

[Simon]

He's just had a reply from Brian, and that was indeed the case, apparently due to too many failed login attempts.