Why is my client receiving plain text emarketing?
Emarketing sent from your website is sent in HTML format by default. If it appears in plain text for the recipient, either their email application is converting the email to plain text format or their email server is doing this before it arrives in their email application.
There is no way for us to tell which one is the culprit, but it is most likely the settings in their email application. The recipient may need to check the setup of their email application to change this setting.
Alternatively, they may click the link at the top of the email to view the properly formatted email in an Internet browser window.