imap.mail.yahoo.com is the ATT.net SMTP server
993 is the SMTP port number.
SSL / TLS is required for IMAP Security.
Your Email address is your IMAP username.
Your ATT.net email account password is your IMAp password.
Read more here:- https://www.datarecovo.com/att-net-email-login/
Click Mail in your Mac's toolbar, then select Preferences from the dropdown menu.
In the left sidebar, select the account you want to connect to HubSpot.
Select Account Information.
Find the field for Incoming Mail Server. This value is your IMAP server name.
Next, find the field for Outgoing Mail Server. You may need to use the dropdown menu to select Edit SMTP server list to view the SMTP server name. You can also find your SMTP port here.
Regards,
Bruce