Currently (as stated in the title) running Exchange 2003 with Outlook 2007 clients Message recall seems to work or not work on a random bassis. Is there any settings in exchange that could prevent it from working on certain occasion? So far, the message wasn't read by the user and no rules seems to affect it, but still it doesn't work on certain times. Thanks!

No specific setting, what issue do you get? Does it fail for all user in the message or some? Do you get a report back?Sukh

In Exchange Message Recalling is an Outlook feature. So no Exchange provides no settings to control this. Recall requests only get processed when the recipient opens his Outlook client. If the Recipient Outlook was closed at the time when you sent the recall request, the request won't be processed automatically. There are so many reasons why message recalling might fail to work, I did better refer you to these articles: How Exchange Message Recalling Works http://www.exchangeinbox.com/article.aspx?i=181 Message Recall Success! ...kind of http://www.exchangeinbox.com/article.aspx?i=183IMF Tune - Anti-spam extending the Exchange 2003, 2007, 2010 IMF/Content Filter - http://www.windeveloper.com/imftune/

Thanks, I think it covers it pretty much. Basically, Cache mode is helping it, Outlook is doing it once it's opened Rules might prevent it