I've tried several things now to get rid of the html-formatting in the body of the invoice-mail sent off to customer. I've tried to disable tinymce and set textarea to wrap=hard, but all text just ends up on one line in the mail-body. I also tried to set $mail->IsHTML(false) in email.php. But all without any luck :-/
currently we use phpmailer for our emailing, you might want to have a quick read of there documentation http://phpmailer.codeworxtech.com/ - there may be a way to turn html off apart from isHTML(false)
let us know how you go - a few other people would like to see how this is done
The email that is sent has header with "Content-Type: multipart/mixed". In Thunderbird I have to set the body to be shown as pure text to get the correct formatting; i.e. with line breaks. If a chose to show the body as html, then all text ends up on one single line.
This scenario doesn't occur with other emails in Thunderbird.
i don't have an immediate solution for you but we may look at replacing phpmailer with Zend Mail (part of the zend framework) in the near future - which should make html/text straight forwared to use and config
