Many things have changed since the release of the second edition of this book. That edition covered sendmail through V8.8. Since then, V8.9 through V8.12 have been released.
Unfortunately, there is no completely satisfactory way to indicate all those changes within the text proper of this book. Instead, we have elected to list the changes in this appendix, ordered by the chapter in which they are described, and thus, essentially by subject.
Note that in addition to describing new sendmail versions, this edition of the book also offers three new chapters that cover performance tuning, spam handling, and sendmail’s companion programs.
Also note that this appendix is not the final authority about new items in sendmail. Instead, you should read the RELEASE_NOTES file supplied with the source distribution.