First check that the onetel mailbox is working and that you know the password.
Select here: Sign in to TalkTalk Mail
Enter your full TalkTalk Mail onetel email address, select Continue and enter the onetel email password, select Sign in.
Then follow the guide below:
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
Setting up TalkTalk email on iPhone
Add the onetel email account and then check the settings to confirm all is added correctly. NB All TalkTalk mail domains including those in the onetel family, all use the exact same settings and talktalk.net host servers.
