SMTP TLS Handshake failure - can't send emails since switch to Gmail

[wireless]

I am using The Bat email client on Windows. Since switching over to the new Gmail system for telus.net email I'm unable to send email.

I have correctly configured the SMTP settings as per the instrucitions - smtp.gmail.com, account authorization, TLS, SSL, port 587. I keep getting a "TLS handshake failure. Invalid server certificate (The certificate cannot be used for this purpose)." error. I have tried several times to reenter the information etc. but continue to get this error. I can receive pop3 email as expected.

How can I get this working so I can send email again?

The full log contents:

9/1/2020, 23:32:30: SEND - Connecting to SMTP server smtp.gmail.com on port 587
9/1/2020, 23:32:30: SEND - Initiating TLS handshake
>9/1/2020, 23:32:30: SEND - Certificate S/N: 713A9E4A4A0F35CD020000000077BAC2, algorithm: ECC (256 bits), issued from 8/11/2020 8:57:38 AM to 11/3/2020 8:57:38 AM, for 1 host(s): smtp.gmail.com.
>9/1/2020, 23:32:30: SEND - Owner: "US", "California", "Mountain View", "Google LLC", "smtp.gmail.com".
>9/1/2020, 23:32:30: SEND - Issuer: "US", "Google Trust Services", "GTS CA 1O1". Valid from 6/15/2017 12:00:42 AM to 12/15/2021 12:00:42 AM.
>9/1/2020, 23:32:30: SEND - Root: "GlobalSign Root CA - R2", "GlobalSign", "GlobalSign". Valid from 12/15/2006 8:00:00 AM to 12/15/2021 8:00:00 AM.
!9/1/2020, 23:32:30: SEND - TLS handshake failure. Invalid server certificate (The certificate cannot be used for this purpose).
!9/1/2020, 23:32:30: SEND - The server has aborted the connection
9/1/2020, 23:32:30: SEND - connection finished - 0 message(s) sent
9/1/2020, 23:32:30: SEND - Some messages were not sent - check the log for details


More...