I've just moved to TalkTalk on 20th February and having a really strange issue with TT email.
I created a new email address which ends in @talktalk.net via the portal, I can log on to this account via webmail, I can send emails from this account which are received successfully (external email address).
I cannot receive any emails though, I've tried a reply from the external email account, I also sent an email from this account to itself via webmail, nada, nothing. (It does show up in "Sent" folder as normal).
Another thing that might be related, I cannot log on to the account with an email client, I've tried Outlook (pop3 and imap) and a Windows phone. It just gives an authentication error.
I've logged a call with TT but it appears to have gone to the wrong team, I just got a SMS to say they're checking my bb line!