Simply replace the unfilled areas such as "" and "[date]" with your information.
I would like to take this opportunity to express my thanks for your participation at our [name of conference] conference. The Chairman and board members have asked me to pass on their sincere appreciation for your efforts.
Your skill in chairing the controversial panel on [name of topic] was very much appreciated by those representing all sides of that topic. As well, we have received many post-conference requests for the paper you delivered on [name of paper].
On both a professional and a personal level, I really appreciated the time that the two of us were able to spend together. I certainly learned a lot about the unique aspects of [topic of appreciation] in your part of the world.
We are currently hard at work producing the conference proceedings document, and we expect to be sending it out to all participants soon.
Again, thank you so much for your enthusiastic participation in our conference.
Please keep in touch, and drop by any time.