When an e-mail with a Html body is sent with mail.sendmail, two views are generated (html and plain text). The html body is converted into plain text using the method ConvertToText.
The conversion is pretty simple, br-tags are converted into new lines, afterwards all tags are removed, and the inner text remains.

A custom module sends emails with inline CSS inside < style > tags. In that case the css itself is turned into plain text.

Steps to reproduce:

• Prepare yourself to examine the messages send from your dnn installation, for example with papercut

• open admin->newsletter

• enter some text into the body, then switch to html view

• add some style like < style type="text/css"> any style < /style>"

• send message and verify the plain text view ofthe email

Expected:

only the text is shown

Result:

text and style is shown