Preferred email type text vs html

[Anonymous]

Is there a built-in function for sending text vs html version of an email based on a lead's stated preference?

[Anonymous]

Currently Marketo sends both the text and HTML versions of the email and the recipient’s email client chooses which version to display based on the user’s preferences. 

Unfortunately Marketo does not have an option to force sending a text only email, much less conditionally, but this is a good idea and you may want to vote on and contribute this additional suggestion to the existing Idea Option to text only emails.