Usually people sounds either mildly jocular or very odd as a mode of address.
Many people are unsure of what salutation to use in a letter. Unless you know the person well, it's best to use a formal salutation versus a casual one.
"Dear" is what people use it nowadays.
Walmart greeters must give salutation to all who enter the store.
When producing a mail-shot to prospective customers, what should be the salutation.
"Dear Friends" might work.
After the salutation of a business letter, the correct punctuation to use is a colon.
A good salutation for a church foundation letter would be 'blessings'. You could also use your normal salutation such as 'sincerely yours'.
Dean actually is the proper salutation. One could say: Dean Redmond, would you please sign this form? Alternatively you could just use the Dr. salutation or the Professor salutation if those are appropriate, which they generally are.
The Reverand and Mrs
It's etiquette and a form of salutation. On should say, 'Hello' to someone in business, but, if a friend you can use the short form of 'Hi' or any form of salutation (Example: slang) 'Yo there babe!'
Use the name of the person who wrote the letter, and write a formal letter. Use the salutation "Dear Mr. ____" or "Dear Mrs. _____" as a salutation.
The proper salutation for a man who is a doctor is Dr. David Jones or you can say Mr. David Jones, M.D. either way is ok. If the Doctor is married: Dr. David Jones & Mrs. Jones.