In Exchange Server the term “Out of Office” refers to the ability of mailbox users to configure a message to be sent automatically as a reply to new messages that informs the sender that they are not available.  Sometimes this is also referred to as a “vacation message”.

In earlier versions of Exchange Server there were two settings for Out of Office – on or off.  However starting with Exchange Server 2007 and continuing with Exchange Server 2010 there are more options available to mailbox users for Out of Office.

Internal vs External

Unlike previous version of Exchange a mailbox user on Exchange Server 2007 or 2010 who is using Outlook 2007 or above can configure two distinct Out of Office messages.  One message is sent to internal senders, and the other is sent to external senders.

The reasoning for this makes a lot of sense – the information that is included in an internal message might be more personal or sensitive than that which can be included in an external message.  Or alternatively, the mailbox user may wish to have only an internal Out of Office reply and send no external message at all.

Internal messages have three settings:

• Enabling/disabling the message
• Configuring an optional start/finish time for the Out of Office period
• The Out of Office message itself

External messages also have three settings:

• Enabling/disabling the message
• Whether to reply only to senders in the user’s Contacts list
• The Out of Office message itself

Managing Out of Office Settings

Mailbox users on Exchange 2003 or earlier (for example in an Exchange organization that is part of the way through migrating to 2007/2010) only have the single, legacy Out of Office message available to them.

Mailbox users on Exchange 2007/2010 who use Outlook versions prior to Office 2007 are not able to configure the internal and external replies using Outlook, and must instead use Outlook Web Access.

Mailbox users on Exchange 2007/2010 who use Outlook 2007 or later are able to configure the internal and external replies using Outlook, and can also use Outlook Web Access.

The administrator is also able to manage an Exchange 2010 mailbox user’s Out of Office replies using either the Exchange Management Shell or the Exchange Control Panel.

For example, this mailbox user has automatic replies configured.

[PS] C:>Get-MailboxAutoReplyConfiguration alan.reid

Identity       : exchangeserverpro.local/Users/Alan.Reid
AutoReplyState : Enabled

The administrator can disable the Out of Office setting if required.

[PS] C:>Set-MailboxAutoReplyConfiguration alan.reid
 -AutoReplyState Disabled

Restricting Out of Office Messages

In some businesses the security policy is to not allow Out of Office messages to be sent outside of the organization.  However this policy may also need to be relaxed for certain trusted partners.

This managed in the Exchange Organization settings for Remote Domains.  By default a single * (asterisk) Remote Domain is configured which permits Out of Office messages.  If the above security policy was in place this can be set to allow no Out of Office messages.

[PS] C:>Get-RemoteDomain | fl name,*oof*

Name           : Default
AllowedOOFType : None

To permit Out of Office messages for a trusted partner the partner’s domain name is configured as a Remote Domain, and configured to permit external Out of Office messages (this will be enabled by default when the Remote Domain is created).

In summary, Exchange Server 2010 permits total control and flexibility of Out of Office messages for both the mailbox users and the administrators.