[$] The trouble with text-only email

By corbet Mozilla’s manifesto commits
the organization to a number of principles, including support for
individual privacy and an individual’s right to control how they experience
the Internet. As a result, when Mozilla recently stated its intent to
remove the “text only” option from its mailing lists ā€” for the purpose of
tracking whether recipients are reading its emails ā€” the reaction was, to
put it lightly, not entirely positive. The text-only option has been
saved, but the motivation behind this change is indicative of the
challenges facing independent senders of email.

From: LWN