Grant group Read access to ALL mailbox calendars

Version of Exchange?
This is something that has to be set per mailbox, so it cannot be set to inherit on new mailboxes.
Therefore once the version of Exchange has been established, you would need to have a script running each night (For example) to apply the permissions for anyone new or has removed the permission.

Simon.

Sorry, running version 2010.
Thanks Simon

Hi Simon
Unfortunately the code error-ed out straight away

Get-mailbox : The term 'Get-mailbox' is not recognized as the name of a cmdlet, function, script file, or operable
program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ Get-mailbox | Foreach-Object { Add-MailboxFolderPermission ($_.Alias + ":\Calend ...
+ ~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Get-mailbox:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

You were running that from EMS and not plain Powershell?
I tested it before I posted it and it worked fine.

Simon.

Sure from EMS
Odd. I'm out of my office now until monday but will try again then

Hi Simon
I have tried again but same error, even when entering the code in to the Exchange Management Shell.

Regards

Get-Mailbox is a core Exchange command.
The line I gave you I know works as I tested it before posting.

You either don't have the permissions to run the commands or are not using EMS despite what you may think.

Simon.

Stupidly logged in as an administrator without a mailbox.
This worked once logged in as a different admin.

Thanks!

Hi Simon
I have ran your code and now checking random mailboxes (using code get-MailboxFolderPermission -Identity 'username:\Calendar') to see if the permissions have applied however some mailboxes haven't.

It appears if the mailbox already has some custom permissions setup from the default then the new permissions have not been added.

There can be some delays in the changes showing up due to replication within the domain.
Custom permissions shouldn't be a problem UNLESS you are using an account (also a group) that already has permissions. In that case you have to use set- rather than add- because you are changing the permission.

Simon.

Hi Simon
I have tried the command with Set and Add but there are a number of maibloxes where the new permissions are not appearing.
Ihave waited until the next day to check permissions.

You shouldn't need to wait a day, the permission should show within a few minutes.
Are you sure the end users aren't taking the permissions out?
Check also that permission inheritance is enabled on the user account in ADUC.

Simon.

Thanks for your help with this!

I need to set these permissions because our users don't know how to it themselves, so I am confident it's not them changing them back.

Where do I check permission inheritance in AD?