Hi We have a slightly unusual request that I was hoping for some assistance with :) At the moment here is the situation: Email/ AD domain name: company.com Exchange 2007, AD 2003, Outlook 2007 Mail server: mail.company.com DC: dc.company.com However, we have a business unit (Marketing) that has been transferred to a sister organisation. They have a seperate AD forest/Exchange org. Our network and theirs are connected by WAN. Email/ AD domain: Partner.com Exchange 2007, AD 2003. Mail server: mail.partner.com DC1: dc.partner.com Problem is - Marketing will remain in our offices, using our machines. They want to continue to access their file shares, PC's etc using their existing AD accounts - Company\User1 etc. BUT - they want to use Partner's mail system. So basically, they will log on their PC using their Company AD accounts, but use a secondary logon to access their Exchange mailbox which would be hosted on mail.partner.com So I figure we reconfigure their Outlook profile to point to mail.partner.com - no biggie. The secondary logon would take care of access. But we had the following concerns: i) When they try to access Outlook, they will be prompted for credentials. Is there any way we can pre-populate the login box account name (e.g. "Partner\User1" ) so that the users only have to enter their mailbox password. Or should this happen automatically? ii) When we reconfigure their Outlook profile - should we 'change' their existing profile (i.e. point it to mail.partner.com) or create a new profile altogether? iii) Marketing generally email each other - so there will be cached entries in Outlook which I understand will use the legacyExchangeDN value to route email. But I guess the legacyExchangeDN will be different in a different Exchange org - how can we ensure that cached autocomplete entries continue to route to their recipient? iv) For non-Marketing but other Company users, what would happen to cached entries in Outlook when trying to mail them? Would Outlook understand that they were from the 'old' domain, and so use SMTP to route the mail?

Is there a trust involved? How much control over the second Exchange org do you have? If there is a trust, then you can configure authentication to use the trusted domain. If there is no trust, then you will have to cope with the prompt, at least initially. The remote domain needs to authenticate the user. There are various ways to get Outlook to remember it, but that isn't always a good idea, particularly if security is an issue. When it comes to the cached entries, the only way that can be made to work is if custom entries can be put in Exchange of the server they are migrating to. However, new profiles will be required, which will almost certainly mean a new nick names file. Your best option might be to find one of the nick name export tools, and import the non-local names in to a new one. Then allow the internal names to build naturally. They only need to select the user once from the GAL for the nicknames file to populate. Simon.Simon Butler, Exchange MVP. http://blog.sembee.co.uk , http://exbpa.com/

Hi Simon Thanks - we can add a trust if we wanted to, but I thought that the secondary logon would take away the need for that? Re. the cached entries - isn't there a file where all the cached entries are kept (I'm not actually sure what it's called though). I figure if we could re-import them into a new Outlook profile, people would still have their autocompleted entries. The question is, once they are using the new profile and pointing to a new Exchange server, would Outlook try and resolve the non-local entries (i.e company.com) via SMTP, or still try and use some sort of legacyExchangeDN value? Is it possible to add the legacyExchangeDN from the old org into a new address somewhere so they contiune to resolve?

The nicknames file is the autocomplete entries. While moving that file around works fine for SMTP entries, for internal Exchange entries it can be tricky to get it to work correctly. http://blogs.technet.com/sbs/archive/2009/05/21/cannot-reply-to-old-emails-or-modify-old-calendar-items-after-pst-mail-migration.aspx Outlook will query the local autocomplete first, then the local contacts, then the GAL. If there is a matching entry in either of those two then it can resolve to that. Trying to bring a nicknames file across is not something I usually recommend because of the inconsistence results. Simon.Simon Butler, Exchange MVP. http://blog.sembee.co.uk , http://exbpa.com/

Have you considered the linked mailbox for these users? Since these users will use the mailbox system in another forest, you can link the user accounts to the mailboxes in another forest so that the authentication will use users’ current credential How to Convert a Mailbox to a Linked MailboxJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com