You wouldn’t start off an e-mail with “My Dear X”, or “Dearest X”, since that would be too personal for a professional email, so “To X” being more impersonal seems like it would make the letter more professional-sounding, compared to “Dear X”.
You wouldn’t start off an e-mail with “My Dear X”, or “Dearest X”, since that would be too personal for a professional email, so “To X” being more impersonal seems like it would make the letter more professional-sounding, compared to “Dear X”.
Email already has a To: field. There’s no point in writing it in the body.
A professional email would be the same as an informal one. Start with “Hello!” or “Good morning!”.