If you are seeing this issue for all candidates that you attempt to send the Take Home Test to, it is possible that the attached file exceeds the size limit that most major email providers will accept, which is typically 20 to 25MB.
If you identify that your attachment does exceed this limit, we would recommend reducing the size of the file or choosing to send the test docs in a hosted link, such as Google Drive or Dropbox. This should resolve the issue you are seeing and allow these emails to be properly sent and received, without running into any issue!
Applies-To: [Greenhouse Recruiting]
Keywords: [Take Home Test, file size]