Is it okay to use forms in emails? It's not the best idea. But what do you say when your boss asks you to put one in an email? You can either tell them "no" for reasons which may not make sense to them, or you can back up your defiance with some hard evidence.
The short of it is that email clients consider email forms to be a security risk. While some email clients simply warn you of potential danger, others outright disable the forms. So if your boss wants to send out a form, they should know that most of their recipients will never be able to use it. And for those who can, they'll think twice about submitting data when they see a warning from their email client.
Given the sporadic support for forms in emails, we recommend linking to a form on a website rather than embedding it in the email. This is the safest, most reliable solution to pairing an email message with a form. More people will see it and be able to use it, and as a result participation will increase.