After installing McAfee VSE/HIPS component in client machine consistently asked to re-enter user credentials for Outlook when un-docking laptop . This was not the case before installing McAfee components.
Previously Symantec was installed in these computers.
Its like undocking machine when outlook is opened and connecting it to VPN the password prompt appears from outlook. But when disconnected from wired to wireless connection there is no such popup appearing.
Any settings need to be changed to resolve this issue.