Hi all A quick question if I may please. We have a global company we support and they have just upgraded their Brussels office from Exchange 5.5 to 2003. The 5.5 server is still in place and working at this time. The upgrade was done about 3 -4 weeks ago. Before they could share Calendar information between themselves and people in the Amsterdam office, who are still on 5.5, and vica versa. I assume this should not be a problem now they have upgraded? I assume Calendar sharing between 5.5 and 2003 in different Sites is possible? I have hunted high and low for information on this to little or no avail. I have checked the ADC and I note that the Amsterdam office has no connection agreements at all? Is this an error please? Each site is a separarate AD and Exchange site as well as both being in their own Domain with their being a two way trust relationship in place. Any help or ideas would be most greatly appreciated. Many thanks in advance, Regards, Paul Lemonidis.