The accept or decline buttons show up with internal domain addresses, but as soon as you throw an email address in from outside of the domain, none of the recipients are able to accept or decline. Is there a setting in the exchange management console or command line that will enable this option for anyone we send meetings to? I've searched all over the net for the answer, but have had little luck! I should add that we utilize GFI mail security, if that is any help. Computer Systems Specialist

Anyone? I have to think there is someone here who had this same problem at one point?Computer Systems Specialist

After doing some digging, I found the answer to this mystery. I will post here for future reference. Turns out that our disclaimer that goes out with external emails is formatted in HTML, which breaks the formatting of the meeting request. I think you can somehow enable Rich Text as your disclaimer format, but we did not have it on our mail essentials through GFI. Doing what is suggested below keeps the disclaimer from going out for meeting requests. Via GFI's site. Article ID: KBID003560 Issue Encountered : A user accepts a calendar invite from an external sender, by selecting "Send the response now" within Microsoft Outlook. The meeting organizer receives a blank email as a response More Information : This issue occurs when GFI MailEssentials is installed on Microsoft Exchange 2007. GFI MailEssentials adds a disclaimer to outbound Microsoft Outlook appointment and meeting requests. The disclaimer modifies the notification in such a way that makes it unreadable in Microsoft Outlook. Solution : The following procedure explains how to disable GFI MailEssentials from adding disclaimers on responses to Microsoft Outlook appointment and meeting requests: Open the following file using a text editor such as notepad: <GFI\MailEssentials\Data\product.config> Add the following line as the last key on the line before the closing </appSettings> tag. <add key="DisableOLMeetingDisclaimer" value="1"/> Restart the Microsoft Exchange Transport Service from the Services console (a reboot of the server is what I plan to do). Computer Systems Specialist