We are doing this for many of our users. See my <a href="http://itknowledgeexchange.techtarget.com/it-trenches/2000-users-new-mailboxes-one-weekend-done/">blog posting</a>. One thing that your users will encounter is the issues with the ability to preview/look at attachments within the message. The attachment will have to be opened outside of the message using the appropriate application. This is more of an annoyance than a real issue. Other than that, I am not aware of any coexistence problems in our environment. ------------------------------------------------------------------------------------------------------------------------ Outlook 2007 is backwards compatible. The functions shared with outlook 2003 and the rest of office 2003 should not be diminished. ******************************************************** Although it will not create any technical issue as such but you will have many functional issues like attachments or any other similar compatibility issues. Microsoft does not recommend to run a single current component of a product running on a PC with older version of the product.

We are doing this for many of our users. See my <a href="http://itknowledgeexchange.techtarget.com/it-trenches/2000-users-new-mailboxes-one-weekend-done/">blog posting</a>. One thing that your users will encounter is the issues with the ability to preview/look at attachments within the message. The attachment will have to be opened outside of the message using the appropriate application. This is more of an annoyance than a real issue. Other than that, I am not aware of any coexistence problems in our environment. ------------------------------------------------------------------------------------------------------------------------ Outlook 2007 is backwards compatible. The functions shared with outlook 2003 and the rest of office 2003 should not be diminished. ******************************************************** Although it will not create any technical issue as such but you will have many functional issues like attachments or any other similar compatibility issues. Microsoft does not recommend to run a single current component of a product running on a PC with older version of the product.