How to enable or disable Out of Office replies in Exchange 2007

How to enable or disable Out of Office replies in Exchange 2007

for a single user:
Exchange 2007 lets administrators control per-user external OOF messages using the Monad command "Set-Mailbox" with the "ExternalOOFOptions" parameter:

MSH>Set-Mailbox -id -ExternalOOFOptions [InternalOnly,External]

By default, per-user external OOF option is set to allow external OOF. By setting this to "InternalOnly" for a given mailbox, instead of "External", that mailbox will not be able to send OOF messages outside the company, using any client, regardless of what the user selects.

for an entire domain:

MSH>Set-remoteDomain -Identity -AllowedOOFType [None,InternalLegacy,Internal,External(Default)]

The AllowedOOFType values are as follows:

None: This blocks all OOF messages to the target domain.

InternalLegacy: This allows either Exchange 2007 internal OOF or OOF set by Outlook 2003 or earlier clients to be sent to the target domain but blocks Exchange 2007 external messages from being sent to the target domain. You would use this setting with a close partner company who you wanted to receive your internal OOF messages. You would also use this setting in a cross-forest environment where one company had multiple Exchange deployments.

ExternalLegacy: This setting allows either Exchange 2007 external OOF or OOF set by Outlook 2003 or earlier clients to be sent to the target domain. If you already allow OOF messages to flow outside your company, you probably want to use this setting, so that existing Outlook 2003 users do not see any change in behavior.

External (the default): This setting allows only Exchange 2007 external OOF messages to be sent to the target domain but blocks internal OOF messages or OOF messages set using Exchange 2003. If you currently block OOF messages to other domains, you probably want to use this setting in order to keep the same behavior for Outlook 2003 users but allow Exchange 2007 external OOF messages out for those who specifically choose them.

Use the wildcard '*' for the target domain if you wish your per-domain OOF settings to apply to all external domains that don't otherwise have a specific setting for them.

source: http://msexchangeteam.com/archive/2006/10/06/429115.aspx