You can't embed a form into email as email clients don't support the technology required for embedding our forms.
A great workaround, however, which many services do, is to include the first part/question of a survey as an image in the email and then link it to the form. So when the respondent goes to answer, they are taken to the page.
You can always share a link to your form as well. You can get the link to your form under the "Share" menu in the form editor.