Where I work we have been told to just start emails with "Good afternoon" or "Colleagues", and similar in briefings, to make everyone equal in every respect. This is removing the military distinctives from what is principally a Civil Service and industry driven workforce.
In order to satisfy the above it is better to add another addressee, even if they don't need to know, and needlessly fill their Inbox otherwise one has to be more specific in appropriately addressing the military superior using the 'S' or 'M' word which could be offensive if one has not been privileged to see their choice of pronouns in their signature block!
