Hi jedmonds
Your lineone mailbox got limited to webmail only because either the android phone, tablet or Outlook email was still using insecure settings. Even though you have a TalkTalk Business account that only entitles you to webmail access. Full access is for TalkTalk MailPlus subscription customers. Advice about MailPlus is below. But to enable you to decide about subscribing let's see about getting the mailbox working with secure mail settings.
If you saw the message from TalkTalk advising "Our records show that you are still accessing your email using unencrypted email settings, because of this you will no longer be able to receive or send emails via this email app or software" then the email address receiving that notification has been limited to webmail only access as a last resort action by TalkTalk to stop the use of insecure email.
TalkTalk Mail webmail is secure by design 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.
You will be able to get email access restored to email apps or software including mail collection services, passwords will then re-authenticate, so long as you're ready to use up to date and secure email settings for all the ways you view emails. We can advise on device and software compatibility 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.
The Android and Outlook device guides are included below. What version is Outlook? Outlook 2016 or newer are supported for secure mail.
For a definitive check of 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
