Hi,
Thank you for posting your query on Symantec community & would be glad to answer your query.
If there is a proxy in the environment it will be necessary to configure the proxy settings in the Symantec Endpoint Protection Small Business Edition (SEP SBE) cloud management console, this document will provide instructions for this process.
Can Manually Configuring Proxy Settings on an Existing Client as well. If proxy settings are entered incorrectly and clients loose connectivity, the correct settings will need to be applied individually on each computer, to do this:
Follow the steps given in this article:
Article: How to configure Proxy Settings
URL: http://www.symantec.com/docs/TECH212344