Service Status (Email) is flagging up an issue with signing in and noting that the TalkTalk team are on the case. However, it's a slightly different circumstance you're reporting and we've seen this before when some Internet Security software on your device is holding up the sign in.
Kaspersky Internet Security is the one reported most.
The article Problems with TalkTalk Mail covers this issue. To troubleshoot, simply disable or turn off, just on a temporary basis, the scanning of any Anti-Virus or Internet Security Software and let us know if you can then sign in to TalkTalk Mail.