We're seeing many legacy mail users upgrading to the TalkTalk Mail platform using weak mailbox passwords.
So, before the system suspends your use of the mailbox please take time to upgrade your legacy mail password.
Hopefully you'll have pre-registered for password recovery an alternate email address and mobile number. Either can be selected in the password reset process to receive an emailed link or a 6 digit code by mobile text message to authenticate a password change. It's worth checking these are present and correct before opting to change the password.
My recommendation is to exceed the minimum required and use a 12-15 multicase letters and numbers password that also includes a symbol. Created from multiple words gives an opportunity to memorise the password that, for security, needs to be unique to the mailbox. The Internet browser that you use for TalkTalk Mail may also offer to generate a secure password and will save the login for you.
If using TalkTalk Online Defence then bundled with the security package is a Password Manager that is useful for generating unique passwords and keeping those secure passwords ready for a sign in.