Hi all, exchange 2007 SP2 we do not use autodiscover as the url and we use mail.mycompany.com. now, we have two-way trust between two forest A (exchange 2007) and forest B. the users in forest A go to forestB and the autodiscover does not work. can not autoconfig emails by using outlook 2007. What might I miss?

I believe in that any time you go cross forest you will need to use the name autodiscover. Calendar sharing I know works that way and I assume a resource forest would require it as well. If this is all internal (behind a firewall) this is just adding a DNS "A" record in the SMTP namespace for users in Forest A for autodiscover. So that autodiscover.forestAsmtpnamespace.com can be resolved to the CAS servers in the Forest B. You will need an SSL cert that has that FQDN name on it as well.Chris Morgan

The fact that you are using a trust doesn't mean anything when it comes to autodiscover. Autodiscover internally is pulled from the domain. Those machines in the other domain cannot see the autodiscover information. Therefore you must treat them as external machines and that means having autodiscover DNS entry or the SRV record enabled. If you use autodiscover DNS entry then it will need to be part of your SSL certificate, otherwise you will get errors. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources

I add autodiscover in the forest A. I mean this user has mailbox in the forest A and this user is in the forest A. When this user went to Forest B office, (not move or migrate and just for a trip), then can not autoconfig emails by using outlook 2007 when he used different computer. I do ctrl+outlook and test autodiscover and the result succeeds. anything I miss?

Are you doing anything with DNS to allow autodiscover records in the DNS zone for the Forest with Exchange in it to be resolved by the trusted Forest? Secondary zone, or something like that? Simon.Simon Butler, Exchange MVP Blog | Exchange Resources

>Are you doing anything with DNS to allow autodiscover records in the DNS zone for the Forest with Exchange in it to be resolved by the trusted Forest? Secondary >zone, or something like that? I use DNS conditional forwarders (windows 2003). I can ping autodiscover in domain A from forest B. any other things I can check?

is there a firewall between the two forests? Can you post the autodiscover results you said was working? When you are doing this test how are you doing it? what forest/domain is the machine and user account joined to you are using to test autodiscover? Where are you running this test from (forest A or B network)? Chris Morgan