Has any one heard of this closing????

My boss had me send out letters formated and ending like this

Dear Susy:

(apologies)

With best wishes, I am

Sincerely yours,


Her Name
Her Title

Does this seem appropriate as far as the colon behind a name of a person she knows and how about her closing???? I have never heard of this and she said it is quite common?? Thanks for any help!