Is it a breach of modesty for a woman to address a man in a letter or e-mail by writing “Dear …”
Answer:
Because this has become the normal and formal way of beginning a letter, doing so would not be a breach of modesty. This would be particularly true when the first name is not used, and I recommend “Dear Mr. Cohen” over “Dear Johnny.”
Although it is not a breach of modesty, some prefer to avoid the word “dear,” and prefer to begin the letter some other way.
