Background
SMTP, POP, and IMAP are legacy email protocols that can be easily exploited by online attackers. To minimize this security risk, these protocols are disabled for CSULB email. As a result, if you are attempting to configure your third-party email (i.e., Gmail, iCloud, Yahoo, Thurnderbird) to connect to your CSULB email account AND also use it to send on behalf of your CSULB email account, you will experience an authentication error.
Support
If you have questions or concerns about this, please open a ticket with the Technology Help Desk or call at (562) 985-4959.
For students, if you are only interested in forwarding your @student.csulb.edu email to a third-party account, please see How to Auto-Forward BeachMail Messages. Auto-forwarding is not permissable for employee email accounts.