HTML tag xmlns:v and xmlns:o


I'm trying to add to an email the following <HTML>  tag elements:

xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office"

I have tried with AddAttributeToHtmlTag but it does not seems to work in emails.

Does anyone have any idea on how to accomplish that?

I am trying this approach because the email on outlook won't render the code inside 

<!-- [if gte mso 9]> <![endif]-->


Community GuidelinesBe kind and respectful, give credit to the original source of content, and search for duplicates before posting.