Mysql db: Where can I see if email was received as html or plain?

Hi there, where in mysql db can I see if subscriber received email as html or plain text?

Thank you!

if the email was sent as html and the recipient opened it and the email browser allowed the tracking to be sent back, then that could indicate an 'opened' and it should be shown in the mwz stats (if tracking is enabled and working) which are pulled from the campaign you need to find the campaign related to that html email and then you can find the proof in the mwz mysql dbf