My boss is leaving is this ok for saying goodbye?

Hi everybody

My boss is leaving is this ok for saying goodbye?

"Dear Sir,

It is really sad moments when such good personality leaves our Organization.

It is difficult time when I say goodbye to person who gave me chance to learn many things starting from early negotiations before joining this job until this moment and all various activities in between.

You will be missed but I hope that you will be moving on for better opportunity.

I wish you all the best wherever you go as we always keep remembering you and the good time we spent together .

With my best regards,"