I have a tiscali email account which I believe may have been compromised as I have received emails from that address to one of my other email accounts.
Since I am not a talk talk customer I am unable to change the password.
Have you previously set up password recovery for the email address with an alternate email and mobile number? You could try the Reset your Password option. If you know the existing password you can send a reset to the account itself; if there are alternates listed, see if you recognise them from the hints.
Let me know what you find.