Yes.
Dear Mr. President is a salutation of a business letter. The salutation goes at the beginning, thus that's how you got Dear.
dear your honor
Dear Esteemed Colleagues
salutation
It is not recommended that a writer use "Dear Gentlemen's" in a salutation. "Dear gentlemen's" is referring to the gentlemen's object, not the men themselves. Try using "Dear gentlemen" instead.
A comma should be placed after the salutation "Dear Professor Ortiz."
Dear, or hello
Dear Mr./Dear Ms. followed by their surname.
Salutation in a letter is the initial greeting to your reader and should be addressed accordingly. Depending on who the letter is being addressed to, a salutation can began with Dear, Dear Sir or Madam, To Whom It May Concern, or Hello.
You would normally capitalize nouns in the salutation, Dear Residents: (but this is not a significant aspect of the letter and is often ignored). If you use a longer salutation, such as "My dear Neighbors," the word dear would not be capitalized.
Sir, Dear Sir, Dear Mr. dela Cruz.
Dear ms