It is good practice for the administrator to set at least an initial password when creating the mailbox account. After that, users can change their own passwords based on the password options set up for the account.
If you use the Zimbra directory server for authentication, you can set users passwords. If you use external authentication, passwords are not managed by the Zimbra LDAP server.
Passwords are stored in an encrypted manner in the LDAP directory server. If users forget their password, a new password must be created.
Click Accounts and double-click the account to be opened, or highlight the account and click Edit.
On the General Information tab, enter a new password and re-enter to confirm.
Click Save to commit your changes.
Contact the user with the new password.
Click Accounts to list accounts in the content pane.
Select the account and click Change Password from the toolbar.
Enter and confirm the new password in the Change Password dialog. Check Must change password, to force the user to change the password the next time they log on.
Click OK to commit your changes.
Contact the user with the new password.