This is a friendly, upbeat farewell to someone who dedicated a great part of his/her life to the company. It should express appreciation for the retiree's contributions, as well as bid them a fond farewell.
1234, Main Street
Boston, MA 02123
<Recipient Address Goes Here>
It's with mixed emotions that I say good-bye to someone who has made such a tremendous contribution to this organization over the last <number of years> years. I hate to lose such a valued employee but I'm pleased that you will now get the chance to <plans>.
<Recount events of past years.>.
<First name of retiree>, you will be missed. No one dedicates <number of years> years of service to a company without making an indelible mark on the place and its people. Best of luck on your new endeavors and please come back to see us.
encl: <List of enclosed items goes here>