Now I get second email:
Delivery has failed to these recipients or groups:
The server has tried to deliver this message, without success, and has stopped trying. Please try sending this message again. If the problem continues, contact your helpdesk.
What should I do?
According to johnt.lowe
Please disregard that message. Sorry for the trouble.
As long as you received the "New Request Received" email which includes your ticket number, it is in process.
The original issue on this thread was that no one could submit a form, which was resolved.
The failed delivery email you received occurs only occasionally. Although it did happen once during my testing, neither IT or myself could duplicate it on later attempts.
glad to see that you have found the correct answer to your question. In order to help others with a similar problem to find this answer quickly, we have locked the discussion to keep it focused on the issue you reported.