another for Dear

[sabakaiser@yahoo.com]

i am looking for another more formal word that can be substitued instead of dear. also i thougth of respected sir/madam! please suggest a relevent word my boss wants another word. he is satisfied with the word dear.
thank you
Saba

[Horsa]

If this is a formal letter and anything other than 'dear' is used, it will be wrong.