The easiest way to change the password of a user's Microsoft Exchange mailbox is to use the Active Directory User and Computer (ADUC) console. You can also reset the password from the Exchange Admin Center, but this option is disabled by default. This article describes how to enable the password reset option in the Exchange Admin Center in Microsoft Exchange Server 2016.
1. Log in to exchange server with your admin credentials.
2. Open PowerShell with administrative privileges and execute the following three commands.
3. Log in to the Exchange Admin Center and click on Permissions.
Right-click ‘Organization Management’ and then click Edit.
Click the ‘+’ sign on the roles section. Select ‘Reset Password’ and then click Add. Click OK and then click Save.
4. Log out from the Exchange Admin Center.
5. When you log in again to the Exchange Admin Center and open any existing user mailbox properties, you should see the reset password option.