This is a technical discussion on message dispatching
Rhub's message delivery system is a little complicated because of the hoops it has to jump through to deliver messages across different mediums. Now the trick is, you will not receive a notification if one of your dispatched messages failed to send. Your intended recipient will always be able to view it on the web, so in no way is your message 'lost'. It may be that you are sending the message with the expectation that your friend will get it while they are away from the web. In this case, you would do well to check the dispatch status page to see if there were any problems. Note that some mediums, such as SMS and IM should be reliable, but service providers don't offer any guarantees.
This is how it works:
Please do notify us if there are problems with message dispatching, as it's a little, well, hacky :)
Note: Messages that rhub has considered successfully dispatched will not be shown in your status page.
See also: Dispatched Messages Status