No. Although in other languages the masculine plural is used for mixed-gender groups, that is not the case in English. The accepted manner is to address the audience as 'ladies and gentlemen'.
The collective noun for gentlemen is a "gentlemen." In English, unlike some other languages, there isn't a specific collective noun for a group of gentlemen. Instead, the term "gentlemen" can be used both in the singular and plural form to refer to a group of male individuals of good social standing or behavior.
The relationship between the speaker, the speaker's style of address, and the audience's expectations
gentlemen only ladies forbidden
The term for speaking in second person is "direct address" or "addressing the audience directly." It involves using pronouns like "you" to directly engage the listener or reader.
Use the term Ms. when unsure of marriage status.
This term refers to the impression that the audience receives of the speaker's character.
"Mrs" is the term of address used for a married woman. "Miss" is used for unmarried women and girls.
The relationship between the speaker, the speaker's style of address, and the audience's expectations
A writer's audience is readers that the writer intends to reach.
The term is one word "gentlemen" when used to mean an assembled group of men (e.g. ladies and gentlemen), or male individuals in general. The two words "gentle men" has an entirely different meaning.
It seems only if your familiar, as 'dear' is a familiar term.
The term address means the physical location of something. In email, the term address means the name of the email account where you receive emails.