|Whenever you use text
formatting, the Send Style changes to 'Plain & HTML' if it is not that already.
To send in 'Plain Text' means just to send a text
email, with no formatting, any formatting that there is will be stripped off.
To send in 'HTML' means that the email will
only be sent in HTML, this may cause problems if the recipient cannot receive HTML emails.
To send in 'Plain & HTML' means that the
email will be sent with two parts, the first part will be plain text, with all formatting
stripped off and the second part will be HTML. This is good if you are not sure whether
the recipient can receive HTML emails.