Depends on what you expecting and what ESM can do. Few words from Console guide ESM (7.0 Patch 1) Page 627:
If you have an integration to an external case management system, you can transfer cases from the
Cases resource tree to the external system as XML by doing the following.
1. Select the Cases resource tree in the Navigator panel.
2. Right-click a case and select Export > Export to External System.
The Case Editor displays a message informing you of a successful transfer. Exported cases also display a
flagged icon indicating the case has been exported. The output file is stored in the Manager’s
archives/exports/ directory.
You are responsible for configuring your external case management system to consume the XML file.
BUT, FIRSTLY:
* ESM must be configured to integrate with ServiceNow® ITSM. Verify with the ESM administrator
who installed ESM. If the integration was not done, or if you upgraded from an older ESM version
when the feature was not available, run the Manager setup wizard and enter the integration
parameters.
Refer to the ESM Installation Guide and follow instructions for integrating with ServiceNow® ITSM in
"Configure Integration with ServiceNow® IT Service Management (ITSM) - Optional".
Refer to the ESM Administrator's Guide and follow instructions for running the Manager setup
wizard in "Running the Wizard."
* After you successfully integrate ESM with ServiceNow® ITSM, the option to export to this application
is enabled on the Console. The integration also adds a field, ServiceNow® ITSM ID, to all case
editors. This field is populated by the system after a particular case is exported to ITSM.
l The ServiceNow® ITSM application must be up and running. You must have login privileges to the
application. You must know how to use the application.
