On Fri, Mar 03, 2017 at 07:13:37AM -0500, The Wanderer wrote: > In order to start a new thread, you have to create the E-mail from > scratch, e.g. by using a "New Mail" button or the equivalent. Creating > an E-mail by replying to an existing message puts the new message into > an existing thread, even if the Subject line is changed.
Or manually remove the In-Reply-To: header, if your mail user agent permits you to do this.