What type of address book is it, Webmail, Outlook (if so, which of the three versions do you have), Thunderbird, or what other email client are you using?
The TalkTalk Community has now moved to a peer-to-peer support model. This means that the TalkTalk team will no longer be here to support with queries. Don’t worry, there are 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
