Hello B.M.Razeen, please adapt this for your use—not really mine, but I got it sometime back from a contact.
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Farewell Message
Dear All,
It is my last day with (company name). I would like to sincerely thank each of you for every experience shared and the good times had during this time. My thanks for the support, and I appreciate having had the opportunity to work with all of you. I have thoroughly enjoyed every aspect of being part of the ___________ group, and I wish you all the very best in the future. Please do keep in touch. I can be reached at my personal email address ([Email Removed For Privacy Reasons]).
Thanks again for everything.
Truly, with due respect,
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Regards,
TS