Hi I sent a reply to a message this afternoon, but it doesn't show up in my sent folder.  The little purple reply arrow shows up on the original message in my inbox. I have had no issues with messages sent later.  How do I know if this message actually went?  I have searched every other folder and can't find it anywhere.  Where could it go?  Would be grateful for any help with this as I can't ask the recipient if they received it.  Thanks