After sending emails they do not appear in app so not sure they have actually been sent
@homealone48 If you took the time to Google search the exact question you’re asking, there are a number of reasons that could be the cause with several links that lead back to many already answered questions on this very forum.
What email app are you using and does it happen with all emails that you send?
Does it happen if you send an email using BTMail on a web browser (webmail)?
Have you checked to see if the emails that do not appear in your apps send folder appear in the webmail sent folder?