On behalf of the United States Postal Service we would like to express our sincere gratitude for all those years of great service and concise delivering. All of your customers will miss you greatly as you have treated them like family. Thank you and enjoy your retirement, you have earned it, no literally you have earned it through all the free work you have done over the life of your career and it's time the USPS pays you for doing nothing, kinda like many postal managers.
This is the speech you should have received, but probably didn't on your last day. Thanks for all your help with questions on this site, from which we hope you don't retire, completely.