express one's sincere gratitude(After four years, I am leaving the post as Mayor of Greenville, and I want to express my sincere gratitude for your support for our shared goal -- building a city for all of us.ART Vancouver)
convey sincere thanks(I would also ask you to convey my sincere thanks and congratulations to all of those other people in your company who contributed in any way to the Helping the Homeless Campaign. – Shaun Fawcett's business letters dimock)
