And... so you spoke to online support... Have you updated whatever email software you're using to use secure settings as recommended by TalkTalk?
Are you receiving mail messages on that software whatever it is? Did you get notified that your email address would have trouble sending and receiving mail messages?
If you saw the message from TalkTalk advising "Our records show that you are still accessing your email using unencrypted email settings..." then the email address receiving that notification has now been limited to webmail only access OR has a stop on sending mail as a last resort action by TalkTalk to stop the use of email connections not secured by TLS 1.2 encryption.
TalkTalk Mail webmail is secure by design when using an up to date Internet browser.
Select here: Sign in to TalkTalk Mail
Enter your full TalkTalk Mail email address and password, select Sign in.
A stop on sending is easily resolved by using currently supported email software and secure email settings as shown in the Email Settings guide below.
If your mailbox is limited to webmail only access for both sending and receiving mail, you will be able to get access restored to email apps or email software, including mail collection services, passwords will then re-authenticate, so long as you're ready to use supported email software and secure email settings for all the ways you view emails.
We can advise on device and software compatibility with TLS 1.2 encryption and provide customer setup guides. Just let us know each mail collection service, each device, its operating system and email software including version that are in current use.
For a definitive check of email settings take screenshots of the incoming and outgoing server settings, image edit to obscure the first part of the email address and upload here using the Camera icon (desktop browser) or Picture icon (mobile browser) above this reply area.
When you confirm the secure settings are ready I can request TalkTalk Support to restore full access. TalkTalk Support will respond here and access will be restored usually within a couple of working days.
Prepare for TalkTalk Support - include in the Community Profile (not in these public posts):
Email account holder name
Scroll down to Private notes to add the email address(es)
and TalkTalk or MailPlus customer account number
Check and Save changes
Select here: Update your profile
The TalkTalk Mail Support Hub is your go to resource for information, guides and Community support for TalkTalk Consumer home broadband and MailPlus subscribers.
Select here:
TalkTalk Mail Support
TalkTalk Mail help
Using TalkTalk Mail
Email settings and device setup guides for TalkTalk Mail
About TalkTalk Mail Plus
