Dear …
Please allow me to extend my warmest thanks of appreciation for the retirement party that you held for me. It was an unexpected honor to be celebrated in this way. How delightful it was to see so many people there. I must say, I enjoyed myself immensely, having the opportunity to do so much reminiscing over old times. Everyone who attended my retirement party made it a most enjoyable and memorable event for me.
“Has it been __(#)__ years already?” I ask myself when I think back. It all flew by so fast. But even so, I am grateful for having had the __(privilege/opportunity/etc.)__ to be part of such a great __(company/organization/type of team/etc.)__. And as I move into this new chapter of my life with enthusiasm about the new adventures that await me, one thing is for sure; I will never forget all those I enjoyed __(working/singing/etc.)__ with over the years.
My experience with __(name of organization)__ was a pleasurable one and I will always remember it fondly. Once again, thank you for the great party and please accept my best wishes to each and every one of you.
Sincerely,