Why do I get a pop-up warning when I use SSL/TLS in my email client?
You may see a warning stating that the mail server you are connecting to attempts to identify itself with invalid information.
This happens when connecting to your mail account over SSL. It is due to the SSL certificate used for the secure connection and the mail server you are using.
To avoid warnings or errors, you can use the recommended SSL/TLS settings, available in Site Tools > Email > Accounts > go to the kebab menu for the corresponding email account > Mail Configuration.