If the external database information has changed (for example, you have installed SQL Server on a more powerful computer with a larger hard drive), you will have to reconfigure Mail Express with the new information. You can run the Mail Express Setup wizard (installer) on the Mail Express computer and provide the new database server host and so on. The database login name specified below must have permission on the database to connect to the database server, read data, and write data.
To modify Mail Express database configuration
Execute the installer on the Mail Express Server computer. The Welcome page appears.
Click Next. The License Agreement appears.
Click I agree. The installer detects that Mail Express Server is already installed.
Click Modify database configuration then click Next. The Choose Database Server page appears.
Click the type of database you are going to use, then click Next. The Database Server Connection Settings page appears with the current database connection settings.
Provide the new connection information. (Refer to Installing Mail Express Server for details of these fields.)
To verify that Mail Express will be able to connect to the database using these settings click Test. If the connection fails, verify that you have entered the configuration correctly.
If the connection is successful, click Save.
You will have to restart the Mail Express Server service for the Server to connect to the new database. (You should do this during times of least user activity.)