It looks like Google has added an additional layer of security to their user's account and as the cTrader platform allows emails to be sent using your Gmail account there is a problem where the email will not be sent. If you look in the cBot or indicator log you will see the following error message.
08/01/2021 07:29:13.944 | Failed to send email "cTrader Email Test". System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Authentication
We recommend that you use a different email provider to set up your email account with the cTrader trading platform.