It is sent through cpanel email function. Have no idea if it is sent through sendmail, SMTP, through an apache handler, who knows. There is no option to send as html. There is NO OPTION to alter the “cron email”. Based on headers it is going through Exim being sent as Content-Type: text/plain; charset=UTF-8. Since it is text, there is no source to look at.
Tried br long ago and as stated above \r\n (in various formats) does not work. The ONLY thing that works is \n\n which gives dbl spacing.