Typically in work you interact with people in three different situations.
One to one.
In a group meeting.
The dream is that they are consistent throughout all three but it is rarely the case.
One to one gives no space to hide and is best for difficult conversations.
In a group means there needs to be a performance to your peers, juniors and superiors. These need to be used for agreements.
Email is open to interpretation and often sent in a rush, so should only be used for confirming information only.
Beware the person with three differenr personalities, one for each of these, they will only ever cause issues through inconsistency.
Make sure you confirm everything in writing and don’t respond in emotion – stay adult to their child/adult/parent.