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3 Messages

Fri, Feb 14, 2020 12:10 AM

Secure email oauth key limited to one email client like outlook at one instance

I've just created an oauth secure email key (per AT&T request) which is used to logon my windows 10 Outlook client. I have 9 AT&T subaccounts where the email was all collected and processed in the windows Outlook client. Now I've been told that only one instance of an email client may be logged in with one account using the oauth secure email key. In effect I can no longer easily use AT&T subaccounts. Surely I am not the first to discover this. What solutions have others found?


Brand User



112.9K Messages

2 months ago

@Allenlee, if you already have your email set up, but want to update your email account with your secure mail key. Here’s what you have to do:


  • Select File > Account Settings.
  • Choose your AT&T email account and then select Change.
  • Confirm or enter the following IMAP or POP settings:Incoming server: (IMAP) or (POP3) 
    Outgoing mail server: (IMAP) or (POP3)
  • Check or enter your User Name (full AT&T email address).
  • In the password field, enter your secure mail key and select the
  • Remember password checkbox.
  • Select Next. Outlook will test your account settings.
  • Select Close, then Finish.

If you use Outlook for email, you’ll have to update your email settings. Learn more about the security upgrade.


Let us know how it works for you.


If you have any additional concerns, please feel free to reach out to us. Thank you for contacting us on AT&T Community Forums!

Lafayette, AT&T Community Specialist

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3 Messages

The secure mail key (SMK) works with Outlook for the primary Member ID email address - both inbound and outbound.

The SMK does not work for subaccounts in Outlook. On the other hand, the account password does work with Outlook. For now, at least, I can send and receive email on all accounts. The big question is will AT&T terminate use of a password and require SMK for subaccounts?

For subaccounts:

The SMK inbound test is successful: "Log onto incoming mail server (POP3)" status is "Completed".

The outbound test "Send test e-mail message" fails. The error message is "Send test e-mail message: The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP)."

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