Alternatively, instead of going down a rabbit hole on assumption of an email delay...bring up the developer tools in the browser, and see what is reported back when you click to submit. The action performed is an ajax request (because it is a reply, as opposed to a full form submit) and the normally expected result would be the content of what you submitted so that page then refreshes to show that.
If an error is displayed (in the response to the submit) then work from there. If no error, then crack on looking elsewhere (such as an email notification delay)