Merge branch 'ag/send-email-edit-threading-fix'

"git send-email" incremented its internal message counter when a message was edited, which made logic that treats the first message specially misbehave, which has been corrected. * ag/send-email-edit-threading-fix: send-email: show the new message id assigned by outlook in the logs send-email: fix bug resulting in broken threads if a message is edited