Just out of curiosity, is there a way to find out how often does Exchange talks to Active Directory? Is there a pattern? Is it once every hour? Thanks.

I always tell clients when asked this type of question to presume "constantly". Take away the DC that Exchange is using and Exchange will die quite quickly - things will stop working within minutes. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Do you know any pattern/algorithm? I'm just curious.

Every time you access something, a query is made to Active Directory. It is then cached by Exchange for up to two hours. To be honest, it is one of those things I simply have never thought about nor care much about. Exchange is very dependant on AD, no AD, no Exchange. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

That I know. I read some white paper that Exchange is 80% active directory. Thanks.

Simon is right, there isn't a specific document out there because it is constant. Any time access or security needs to be verified there is a query to AD. I guess if you really wanted to you could do a netstat command to see the connection, but I am telling you, you just should be happy with the fact that it is constant...especially in a larger organization. here are some articles discussing the integration, after reading it you'll get a better idea as to how many Exchnage services rely on AD: http://technet.microsoft.com/en-us/library/aa996247(EXCHG.65).aspx http://msexchangeteam.com/archive/2009/01/05/450355.aspx http://technet.microsoft.com/en-us/library/aa998561.aspx Jorge R. Diaz, PMP, CCNA, MCSA, MCSE, MCTS Senior Microsoft Consultant Planet Technologies, Inc. Check out My Blog!

Hi Jose, Please see the articles provided by Jorge, especially the second one, it explains why Exchange needs AD, if you have more knowledge about why we need AD, you should get point that when Exchange talks to AD. Best regards, Serena Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.