Hormel attempted to register spam as a trademark when used to refer to "services to avoid or suppress unsolicited e-mails" and the "creation and maintenance of computer software; technical consultancy, particularly in combination with network services; (and) providing of expertise, engineering services and technical consulting services (related to junk e-mail)."

. . . the Office of Harmonisation for the Internal Market (OHIM) . . . . disagreed and dismissed the appeal. Products aimed at tackling the problem of spam were aimed at IT professionals who would not confuse junk e-mail with the meat product, it maintained. In addition, a Google search returned more hits for spam junk e-mail than for the canned meat, which satisfied OHIM that the word was also in use by the general public to refer to unsolicited mail.

A similar dispute is pending in the US, in front of the Trademark Trial and Appeal Board:  Hormel Foods Corp. & Hormel Foods, LLC v. Spam Arrest LLC, TTAB Proceeding (Cancellation) No. 92042134. 

[I would further comment, but I worked on the case while at my former firm.]  [See also InternetCases.com:  Trademark dilution law about to change.]