how to say following in korean,

Hello all,
Respected Managing director, directors of company and my friend.
Today I am so very SAD. Because one of our senior is going back to head office .he has worked here for more than 3 years with us.
I had learned lot of things with him. But now there is some misunderstanding.
I found him very kind heart person but he is very dedicated to office work.

안녕하세요,
존경하는 사장님 그리고 임직원 여러분 (including "my friend")
오늘 저는 매우 슬픕니다. 저희 선임 한분이 본사로 돌아가기 때문이죠.
그분은 여기에서 3년 이상 저희와 일했습니다.
또한, (also) 그분에게서 많은 것을 배웠습니다 그런데 지금은 오해같은게 있어요.

(please check this sentence. I think it's a little bit weird ^^;)
그분은 매우 착한 마음씨를 가진 사람입니다 그리고 회사에 매우 헌신적입니다.