How long ago since you accessed your Tiscali emails? I ask because after 180 days of non-use the email account gets suspended.
After over a year of non-use the account normally gets deleted. Deleted means both permanently erased and unrecoverable and also, for security, not able to recreate the same email address again.
Ah, an email account not used for 8 years will definitely be deleted in accord with TalkTalk policy and for your security will not be recreatable by anyone.
Sorry to be the bearer of the news.
There is a new email service for TalkTalk customers due to launch soon. Here's a peek.
There are also non-ISP email services from the likes of Google (gMail) Oath (Yahoo Mail / AoL Mail) Microsoft (Windows Mail / Outlook) and other smaller providers.