I think you might be seeing this.
http://seer.entsupport.symantec.com/docs/318022.htm
Enterprise Vault overwrites the local proxy bypass settings in Internet Explorer whenever Outlook is opened.
Details:
Enterprise Vault overwrites the local proxy bypass settings in Internet Explorer whenever Outlook is opened.
Workaround:
Uncheck the "Bypass local proxy server" on the Web Applications tab of the desktop policy.
Solution:
This issue has been addressed as part of the following release:
Enterprise Vault 8.0 Service Pack 1 (SP1)
http://seer.entsupport.symantec.com/docs/321953.htm