TO Solve ATT Care Code 205.4, Reset the Settings of Sbcglobal.net Email Configuration

Incoming mail server

For IMAP:- Enter imap.mail.att.net

For POP3:- Enter inbound.att.net

Incoming Server:- 993 for IMAP, 995 for POP3

Outgoing mail server

For IMAP:- Enter smtp.mail.att.net

For POP3:- Enter outbound.att.net

Outgoing Server:- 465 for Both IMAP or POP3

Encryption security is required for both

Read more here:- https://www.datarecovo.com/fix-att-care-code-205-4/