You must have the appropriate Exchange administrative permissions to do so.
Open Exchange Management Console and expand Recipient Configuration.
Select Mailbox option. and then select New Mailbox option in mailbox pane.
In the User Type window, Administrator can choose either to
create a new user or to assign an existing user to the new mailbox. If
Administrator chooses to assign it to an existing user, Administrator will
have to check, if the account already has a mailbox associated with it or
not. Select Next to continue.
User Information: In the User Information window, Administrator has
Mailbox Settings: On the Mailbox Settings page, Administrator can
New Mailbox: In the New Mailbox Window, administrator will get a
Completion: In the Completion window, Administrator will see the
The final screen of the New Mailbox Wizard, shows the
After doing above steps then click Apply and OK button for the screen shown in Step 3.
To create a user using Exchange Management Shell, Administrator can run
the following cmdlet
New-Mailbox –alias <alias> -name <name> -Database <Database name> - Organization Unit Users –User Principal Name <UPN value, example: Anderson@contoso.local>
If Administrator does not type all the required parameters, Administrator will get a prompt asking for the parameters that are missing. In given screen, Password prompt is visible to fill out the password. Users get created after entering the password.