Just what is spam, technically?
It boils down to this: spam is the use of electronic messaging systems to send unsolicited bulk messages indiscriminately. There are circumstances where spamming is illegal under federal law. There are private rights of action available against spammers. That is, people have rights to sue spammers.
No question such a publication is defamatory, if untrue. It connotes civil misconduct and/or possibly criminal behavior by the author. Such a blog, designed to reach a specific group of the author’s potential customers smears the author’s reputation. The blogger is implying that the author and/or his or her work should be discredited. The accusation is intended to injure an author in his or her occupation.
First, take a deep breath and ponder P.T. Barnum’s admonition that “there is no such thing as bad publicity.” Don’t freak out and write a nasty-gram. It’s always better to smooth feathers than to ruffle them. Second, write a friendly personal note to the blogger explaining what you were trying to do. Apologize for any unintended offense. Explain that you are the author and are proud of you work. Perhaps even offer the blogger a free copy. Explain that you made a good faith attempt to abide by the group’s rules and say that you thought that you did. But also explain that what you did was not spam under the law, or as it is commonly understood by the author’s and blogger’s potential readers. Explain that it is damaging to your reputation and that any reasonable person would view the accusation of spamming as derogatory. And then request that the blogger remove the statement from his/her blog or website because it is defamatory. Give them an opportunity to retract and keep a written record of the correspondence. Then, if they don’t remove the accusation and you feel your reputation is important to you and/or you feel you have been damaged as an author, you can consider taking more forceful action.