It would be great if we can check if domains end in a specific domain (e.g. @business.com) so that form respondents can
  1. Not put the wrong email (happens a lot more than you think)
  2. Not put a temporary email service domain (some of them pass as business emails)
Or, have a system that auto-appends the domain at the end. So the user just has to put their username (e.g. johndoe) and then Youform adds the domain (completes it as johndoe@business.com)