Hi @PaulNagami,

I am fairly certain that if you don't see the message in your Canvas inbox, that the student will not see it either.  Being able to reply to inbox email notifications is very fast and convenient, but I would honestly recommend that you reply from Canvas itself if there are urgent messages you need students to see ASAP.  Emails replies could be delayed for a number of reasons: the email itself being delayed in transit, the number of emails Canvas is receiving globally, etc...  With this being the beginning of the year/semester for most schools in the USA, my guess is that the volume of email has increased significantly, causing some delays as the system processes the queue of messages.  You could still reply to most messages via email as long as they aren't urgent, but for the urgent ones taking a few extra steps on your end to reply from Canvas instead of email will probably help the students out a lot!

Hope this helps!

-Chris