Gunicorn worker terminated due to signal 9

Troubleshooting
6

So there is an error with the SMTP settings here. Maybe you should try to change the values for EMAIL_USE_TLS and EMAIL_USE_SSL. You can try with

EMAIL_USE_TLS=False
EMAIL_USE_SSL= True

This is what the documentation sais about these two parameters:

MAIL_USE_TLS

Default: False

Whether to use a TLS (secure) connection when talking to the SMTP server. This is used for explicit TLS connections, generally on port 587. If you are experiencing hanging connections, see the implicit TLS setting EMAIL_USE_SSL.

EMAIL_USE_SSL

Default: False

Whether to use an implicit TLS (secure) connection when talking to the SMTP server. In most email documentation this type of TLS connection is referred to as SSL. It is generally used on port 465. If you are experiencing problems, see the explicit TLS setting EMAIL_USE_TLS.

Note that EMAIL_USE_TLS/EMAIL_USE_SSL are mutually exclusive, so only set one of those settings to True.