*****Install ALL Roll-ups with administrator privileges, open the EMS on exchange and type in: ii (rollup name)******

Problem : 

OWA stops showing a login, or shows an error after a Rollup update.

Solution : 

Need to copy existing scripts for the CAS

or edit the web.config file to point to the location of the assembly dll's

From Exchange Powershell, run following script. (full path included if necessary) ***run as administrator***

updatecas.ps1

(C:\Program Files\Microsoft\Exchange Server\V14\Bin\updatecas.ps1)

Reference Article : 

http://www.msexchangeblog.nl/2010/05/11/blank-page-in-owa-fix-for-exchange-2010/

-to single Modification
Set-CASMailbox -Identity USERNAME -OWAPremiumClientEnabled:$false -Verbose

-to bulk modification
Get-CASMailbox -OrganizationalUnit "OU name" | Set-CASMailbox -OWAPremiumClientEnabled:$false -Verbose

Important:-If you want to enable OWA Premium back to that users you must do those features to true on each user.

-Use below CMDlets to enable it for Specific user

set-casmailbox -identity "USERNAME" -OWAChangePasswordEnabled:$true -OWAPremiumClientEnabled:$true -OWACalendarEnabled:$true -OWAContactsEnabled:$true -OWATasksEnabled:$true -OWAJournalEnabled:$true -OWANotesEnabled:$true -OWARemindersAndNotificationsEnabled:$true -OWASpellCheckerEnabled:$true -OWASearchFoldersEnabled:$true -OWASignaturesEnabled:$true -OWAThemeSelectionEnabled:$true -OWAJunkEmailEnabled:$true -OWAUMIntegrationEnabled:$true -OWAWSSAccessOnPublicComputersEnabled:$true -OWAWSSAccessOnPrivateComputersEnabled:$true -OWAUNCAccessOnPublicComputersEnabled:$true -OWAUNCAccessOnPrivateComputersEnabled:$true -OWAActiveSyncIntegrationEnabled:$true -OWAAllAddressListsEnabled:$true

-Enable OWA Premium for bulk users reside in Spesific OU

Get-CASMailbox -OrganizationalUnit "OUNAME" | set-casmailbox -identity "chinthaka" -OWAChangePasswordEnabled:$true -OWAPremiumClientEnabled:$true -OWACalendarEnabled:$true -OWAContactsEnabled:$true -OWATasksEnabled:$true -OWAJournalEnabled:$true -OWANotesEnabled:$true -OWARemindersAndNotificationsEnabled:$true -OWASpellCheckerEnabled:$true -OWASearchFoldersEnabled:$true -OWASignaturesEnabled:$true -OWAThemeSelectionEnabled:$true -OWAJunkEmailEnabled:$true -OWAUMIntegrationEnabled:$true -OWAWSSAccessOnPublicComputersEnabled:$true -OWAWSSAccessOnPrivateComputersEnabled:$true -OWAUNCAccessOnPublicComputersEnabled:$true -OWAUNCAccessOnPrivateComputersEnabled:$true -OWAActiveSyncIntegrationEnabled:$true -OWAAllAddressListsEnabled:$true

Relevant thread

http://social.technet.microsoft.com/Forums/en-US/exchangesvradmin/thread/0accb305-3923-4898-b28e-6b8944b46a92


Show/Hide public folders button for certain users
============================================

you can use your Outlook client or PFDAVAdmin tool to configure permission on public folders. Using Outlook client set the default permissions to none. You can also set the default so that the folder visible option is unchecked. Then it will not even be visible to those who do not have permissions to it. Add in the users you want to have access the public folder.

Prevent certain users from viewing the global address list
==================================================

Refer below article to know how to hide GAL from certain users

Hidding Global Address Lists (GAL) with Exchange 2007

The Problem:

A 2008 server will not reach the internet

DNS is installed and a static ip is set.

run IPCONFIG /all and the first line of the dns is 0.0.0.0 with your nornal dns entries after.

Solution:

open a administrator CMD prompt

type route delete 0.0.0.0

reboot the server