Troubleshooting:Unable send Batch mail – The SMTP server has unexpectedly disconnected

Question: When I try to send test mail using batch mail at Debtor Statement, error message prompted “The SMTP server has unexpectedly disconnected”. Why?

Version: 1.8 / 1.9 / 2.0

Similar types of error :

The SMTP server requires a secure connection or the client was not authenticated. The server response was 5.7.0 Authentication Required.

535: 5.7.8 Username and Password not accepted.

Possible Reason (1):

Username or password was incorrect.

Solution (1):

Make sure you key in the correct Username and password.
You may try to login your email again to check the password is valid.

Possible Reason (2):

Security setting.

Solution (2):

If you are using Gmail, make sure you allow for Less Secure Apps.
Login your Gmail account > Manage Your Account >Security, then search for ‘Less Secure Apps’. You need to turn on the ‘Allow less secure apps’.