The `SMTP.sendmail` function does not properly handle email CC's and BCC's ([source](https://stackoverflow.com/a/56383008)). Instead of using `sendmail`, we should use the `send_message` function, which properly supports CC/BCC headers.
The
SMTP.sendmailfunction does not properly handle email CC's and BCC's (source).Instead of using
sendmail, we should use thesend_messagefunction, which properly supports CC/BCC headers.