Some advice to authors planning to market their books via email, from experienced editor and author Dr. Euan Mitchell:
Email programs are getting better at detecting advertising material.
Especially if the salutation is not to a specific person's name.
Including an attachment also increases the chances of it being filtered out.
I suggest the best way is to first send an enquiry email to the organisation concerned without an attachment or any advertising copy in the email itself.
Simply ask who the editor of the organisation's newsletter is. This only takes a sentence or two. In that first email, do not explain why you are asking.
Let them ask. And even if you are starting by emailing the organisation's general email address, you should soon have a reply and a person's name to start with. Importantly, the current person, not someone from years past.
The pitch should not be: "Here's my fascinating book, please buy it." People get similar emails all the time and block the sender.
Start a dialogue with an enquiry email, not an ad. If the organisation has a newsletter then it has space to fill on a regular basis. The author might be able to help out : )
Depending on the organisation's main interest, the author might be able to contribute a few quotes or anecdotes to an article.
These contributions need to be customised to the organisation's interests according to the person who answers the emails.
Funnily enough the contributions can include a plug for your book, even if just a footnote at the end of the article. This subtle way of advertising the book should be more effective than a straight-out ad because the author has first been introduced to the reader by the organisation the reader subscribes to.
In summary, the approach shifts from generic inbox drops to personalised email enquiries (or phone calls) about organisations' newsletters without initially mentioning the title.
Don't lead with your chin. Get a dialogue going first. It takes time but the success rate is much higher.