Unless you were trying to register for a TalkTalk system, such as MyAccount that might want to verify your email address, then this is 100% a scam.
From the 29th of March our TalkTalk Community will move to peer-to-peer support and the TalkTalk team will no longer be here to support with queries. Don’t worry we still have plenty of ways to reach out if you need to speak to TalkTalk directly. For more details check out the link here
How to contact TalkTalk Broadband - TalkTalk Help & Support
