Cross Forest Availability Exchange 2010

Posted on 2014-03-19
Medium Priority
Last Modified: 2014-05-14

Here is my scenario:

We have a Domain Trust between 2 organisations who recently merged, let me call them A.local & B.local.

Both domains have exchange 2010, I've configured cross forest availability between them so calendar sharing is possible. I used FIM (Forefront Identity Manager) to sync users of domain A.local as cross forest contacts in B.local. Users from A.local can look up calendars of users from B.local and the other way around, everything just fine by now.

But now the two organisations want to share the same SMTP addresses over the 2 domains. I've configured this by changing the accepted domain as an internal relay domain, so mail for A.local arrives at exchange and delivers it to B.local if the mailbox doens't exist on A.local (through send connector). Mail flow is working fine in this situation.

The problem is the exchange availability (free/busy) between the two domains:

If a user of A.local with primary smtp address userA@ABC.COM want to lookup a calendar of a user in B.local with primary address userB@ABC.COM this doenst work. MX records of ABC.COM are pointing to A.LOCAL. It is working the other way around. An autodiscover record for domain ABC.COM is created an pointing to A.LOCAL.

If you need more info, shoot ¿

Any help appreciated!!
Question by:secuteamers
1 Comment
LVL 44

Accepted Solution

Adam Brown earned 2000 total points
ID: 39940603
Check your Organizational Relationships settings. If ABC.com is not listed as a domain with an organizational relationship, you won't be able to do Free/Busy lookups with other domains that use that domain as a Primary SMTP address. And I'm not 100% sure that even that will work. One way that *will* work would be to make sure that each forest has a different Primary SMTP address, rather than setting up both forests to use the same Primary SMTP domain.

Featured Post

Free tool for managing users' photos in Office 365

Easily upload multiple users’ photos to Office 365. Manage them with an intuitive GUI and use handy built-in cropping and resizing options. Link photos with users based on Azure AD attributes. Free tool!

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

There’s hardly a doubt that Business Communication is indispensable for both enterprises and small businesses, and if there is an email system outage owing to Exchange server failure, it definitely results in loss of productivity.
If there is anything erroneous with Exchange Database, it causes a significant effect on email communication till the user remounts the database. Further, database crash directly affects Outlook users due to which they are unable to access their ema…
Established in 1997, Technology Architects has become one of the most reputable technology solutions companies in the country. TA have been providing businesses with cost effective state-of-the-art solutions and unparalleled service that is designed…
Attackers love to prey on accounts that have privileges. Reducing privileged accounts and protecting privileged accounts therefore is paramount. Users, groups, and service accounts need to be protected to help protect the entire Active Directory …
Suggested Courses

587 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question