I don’t think there is ever an instance where one person is the team, or where one person is responsible for the success or failure of the team. Whether at work or within the family, I believe it always involves a team effort.
Email and texting should never be a substitute for face to face communication or phone conversation. However, if crafted properly, these can be useful in reinforcing your ideas and increasing your influence.
To become an influential leader, the supervisor or manager must transition from a controlling, intimidating or monitoring role to one of a partnership between the manager and employee(s). This will create an atmosphere of shared understanding about what needs to be achieved and the process for obtaining it.