For a professional email, it is preferable as above to address the addressee by name, while including the title of civility of the person followed by his last name.
Ukuze uthole i-imeyili ehlelekile, ingcono njengenhla ukubhekana negama lekheli le-addressee, ngenkathi kufaka isihloko sokuzimela komuntu okulandelwa igama lakhe lokugcina.