The report form[1] is truncated after
Resolving link obfuscation
http://ni2.org/R3uY
The spam was nothing special, just a multipart with a base64 encoded quoted printable text/html, but the space in the decoded URL appears to have stopped the report form generation. Of course the browser will likely handle the URL fine.
[1] https://www.spamcop.net/sc?id=z6405586363z4d5f4c54bcff07193d1ed9bd712c3cc2z