Sent email shown as draft
After your email is sent and there is a message popping up to tell you your message has been sent, the particular email in the email list is still showing as 'draft' (not in the draft box but in the email list) in red for a while. It makes you confused whether the email was actually sent.
Btw, it'd be great if you could provide an option to attach a screenshot. :)
If you still find that the issue is happening, please see this help page for troubleshooting: