Access to the site is blocked by my employer due to a perceived security threat.

"...this web site ( http://htmlformail.com/ ) has been blocked because it has been determined by Web Reputation Filters to be a security threat to your computer or the corporate network. This web site has been associated with malware/spyware."

Maybe something you want to track down, in case the site somehow became listed in a malware database. Sometimes removing sites takes manual effort.