Cannot receive e mail in my Tiscali account

The problem is the messages stored on the server, not the messages that Mail stores locally on your computer. I bet this is a POP account and you have Remove copy from server after retrieving a message unchecked in Preferences > Accounts > Advanced, right?

If you leave this option unchecked, incoming mail accumulates at the server and eventually fills up your account there. Check it and choose the amount of time that Mail should wait before removing a message from the server (I recommend choosing either one week or one month). You may want to click the Remove now button to get rid of the mail that's causing the problem right now.

I have a similar problem, I have just returned from a holiday during which I successfully received my mail on my computer through someone elses server. I hadn't received any mail since my return so tried to access mail through Safari. I can't access the mail section of .mac on my computer. I went to an internet cafe and checked my mail via .mac and had 20 new e-mails that my computer couldn't see. I have a Talktalk broadband account and everything worked perfectly before I left.

I have lots of .mac space available and have recently visited the Genius Bar where they said I have lots of space available re e-mails

I have reset safari, I have deleted and re entered my account details in mail preferences. The situation hasn't changed.

Any ideas?