PlainBodyText defaults to
Content-Type: text/plain which is rejected by Verizon when sent to any firstname.lastname@example.org or email@example.com but if that is changed to
Content-Type: text/plain; charset=utf-8 using
EmailMessage.Headers.AppendHeader then it gets accepted. This is a new requirement by Verizon.
Do any email gurus know why Verizon might have changed the requirement? Should
Content-Type: text/plain; charset=utf-8 be the new default for an
PlainBodyText since it works with every other domain that I’ve tried? If not, is there an easy way to determine when
Content-Type: text/plain; charset=utf-8 should be used instead of