Some managers need reassurance

 

Think of yourself as playing a role in a show, every role has its script.  The actor's personal feelings are never shown.

Management via email requires more of both the manager and the subordinate.  You need to put in more time and energy.  Where the addtional energy goes, you need to figure it out.

Get on the phone more often.

Take more care in your wording when composing email.  Be more courteous, do not go sloppy on the salutation/valediction.  One paragraph for one point for clarity and ease of reading.  Ask at the end the best time to call for his questions, if you think some points might need further explanation, or directions.

Reply to his email promptly.  If you need time for the things he is asking, reply to tell him you are working on it before starting working on it.

Let him feel you treat him like a boss.  In certain sense, having a job is to baby-sit the boss; need to find out his likes and dislikes.