I finished a creative non-fiction memoir about my secret life as a miracle worker. I am using three emails to me from a now deceased wildly popular tech icon. Our phone conversation as well as the emails are positive. Do I need to contact his surviving wife? This could delay my book publication.
I am not a lawyer, but... From the website of the U.S. Copyright Office:
"One of the rights accorded to the owner of copyright is the right to reproduce or to authorize others to reproduce the work in copies or phonorecords. This right is subject to certain limitations found in sections 107 through 118 of the copyright law (title 17, U. S. Code). One of the more important limitations is the doctrine of “fair use.” The doctrine of fair use has developed through a substantial number of court decisions over the years and has been codified in section 107 of the copyright law.
Section 107 contains a list of the various purposes for which the reproduction of a particular work may be considered fair, such as criticism, comment, news reporting, teaching, scholarship, and research. Section 107 also sets out four factors to be considered in determining whether or not a particular use is fair.
The distinction between what is fair use and what is infringement in a particular case will not always be clear or easily defined. There is no specific number of words, lines, or notes that may safely be taken without permission. Acknowledging the source of the copyrighted material does not substitute for obtaining permission."
Now for the analysis. Memoirs and similar personal non-fiction books fall into a grey area of scholastic benefit. They are intended for profit and for entertainment, but the subject matter is not truly educational in the way a textbook is. A biography teaches us about the life of someone else, but that line is less distinct for autobiographies. This is your weakest argument, but can still be reasonably argued with a straight face.
You are stronger on the remaining three elements of the balancing test. The nature of the copyrighted work (emails) is not one that is typically thought of as protected. The reasonable person would think nothing of forwarding an email someone else had written, thereby 'republishing' the initial work. Emails typically are not written for profit and do not involve a large investment on the part of the writer. This lack of expected protection translates into an easement of legal protection.
Item 3 in the balancing test, the amount and substantiality of the portion used, will depend on your usage. Reprinting the entire email in total will afford you less protection than only quoting a line or two. This is in relation to the size of the work, too, so quoting a single line could be a substantial part of a short email.
There is effectively no market for this particular email, so your reprint cannot possibly affect it. This is not like reprinting a famous painting or republishing a book, where your action dilutes the income for the original writer. Unless this particular 'tech icon' also sells collections of his own emails, this particular email should be fair game.
Taking all this together, you have a very strong case for saying your reprinting of the emails constitute fair use. Strong enough that it would be unlikely to spark lawsuits. I have to disagree with the comment that it's always better to get permission. If it would be particularly difficult to get permission (as it would be from the widow of public figure who has no incentive to say 'Yes'), it might be far easier to simply reprint the email rather than jump through the hoops. Doing so would also put you in a better legal state. Republishing a work without permission is better than republishing a work against the express wishes of the family.
Finally, all of this discussion involves copyright law, which is why the phone calls are not covered - being oral and not written, copyright does not apply. Defamation and fraud, however, applies to all of it. Having the right to make a statement does not mean that statement will not still land you in hot water.