Spot the Signs. Again, you may receive this response if you have specialized knowledge that would make it difficult or time_consuming to hire your replacement__or if it would be helpful for you to be actively involved in that search.
After that, you're ready to close out your letter and move on. The basic closings are fine here__again, you don't need to go overly sentimental or formal, but you should also write as if it will be read by anyone at the company. And with that signing flourish, you're done! You've resigned, and you're ready for your exciting new job.