I have recently learned that when I reply back to an email - that my Thunderbird "sends" the email and it goes into my sent folder, but the email is not being delivered. New emails go through When I forward the email instead of reply and put in their address manually it goes through. Can you tell me why when i "reply" to emails they are not going through. Checked ports and settings. All good. I am on a Mac with Comcast internet / email Thanks RC