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Exchange 2007 and Domino Free/Busy Coexistence

I have seen a lot of posts out there in which people have quite a bit of issues with Free/Busy coexistence between Domino and Exchange 2007.  Neil Hobson has an excellent walk through on the site which you can find here.  I wanted to go deeper into Free/Busy configuration, hence this article.

General Information

First of all, in order to get Free/Busy working, you need to go through the pre-requisites noted in the Transporter Suite documentation which you can find here.  This includes getting the Directory Connector configured, installing the Free/Busy Connector on our Transporter Suite Server as well as installing ExchangeCalCon on our Domino Server.  Make sure Domino is configured as a service to ensure there are no problems with Free/Busy Coexistence.

In our migration, we chose to use the Disparate Namespace Model.  So let’s say our domain is, we are using for our Exchange side and for our Domino side.  I will not go into how to configure SMTP to allow for this as this article is focused on Free/Busy.

Some prerequisites before we proceed with configuration:

  • Notes Client (preferably 7.0.2 or above and preferably installed in Single-User Mode)
  • Notes Client configured with an ID File that has access to read the Address Book (names.nsf) and access to BUSYTIME for users
  • Microsoft Exchange Server MAPI Client and Collaboration Data Objects 1.2.1 which you can download here

Network Connectivity

The first thing you need to do is ensure that connectivity between your Transporter Server and your Domino Server which is specified in the configuration of your Free Busy Connector have RPC connectivity between each other.  The RPC Endpoint mapper uses port 135.  Because of this, ensure that port 135 is open.  RPC Endpoint mapper will tell the requesting server to use a specific port above port 135.  Because of this, you will need to ensure just about all ports are open between your Transporter Server and your Domino Server.

Exchange Free/Busy Availability

There are a couple of things you will need to configure here.  When an Outlook 2007 client selects a user from the GAL to add to a meeting, they are selecting a contact based on  These contacts (or mail enabled objects if you are using Quest and used the Contact Merge) have an external e-mail address (TargetAddress) of  Because of this, you must configure the Availability Service so all requests to use public folders.

Because of the use of public folders, you should have an Exchange 2007 Mailbox Server hosting public folders.  In Exchange 2007, if you have more than one public folder database, you should not be hosting public folders on a CCR Cluster.  We ran into issues with this because there are multiple public folder databases in the environment and Public Folders were hosted in the environment (I didn’t do this, it was done before I got there but we ran with it to see what would happen.)  Needless to say, we ended up having to remove Public Folders from the CCR Cluster.  We also had Public Folders on our Transporter Server which contained the Mailbox Role, Client Access Role, and Hub Transport Role.

So for our Availability Service, we will need to run the following command to force all lookups to to use Public Folders:

Add-AvailabilityAddressSpace –ForestName  AccessMethod PublicFolder

In order for the Availability Service to work properly, you need to ensure your Autodiscover Service and WebServicesVirtualDirectory are configured properly.  I have written a lengthy article which will guide you through this.  You can find this article here.

The Availability Service will make HTTP (not HTTPS) requests against Public Folder data.  Because of this, we need to ensure that the /public directory on our CAS does not require SSL. Go into IIS Manager (Start > Control Panel > IIS Manager > Expand Default Website > Right-Click Public > Directory Security Tab > Uncheck require secure channel (SSL))

You will then need to configure your Free/Busy Connector.  Follow Neil’s article and/or the Transporter Suite documentation for this. One thing to note is that the Free/Busy Connector does not actually pull the data from the Domino Server and dump it into Public Folders.  The Free/Busy Connector only searches for Domino created objects within AD and associates Public Folder messages to represent these objects.  The Directory Connector is the connector that will actually pull the Free/Busy data for these users.  I will explain how this works in a bit.

Domino Configuration

Follow the Transporter Suite documentation to configure the Domino Side.  I did not follow the names the documentation had you specify though.  For our Foreign Domain Document, I used ExchangeFreeBusy.

Now this Foreign Domain Document Domain Name is very important as this is how the Directory Connector knows where to pull Free/Busy Information.  When you configure your Directory Connector on your Transporter Server, there is an attribute called ForeignDomain.  Because we used the Domain of ExchangeFreeBusy, you will want to run the command using the Transporter Suite Shell:

Set-DominoDirectoryConnector -ForeignDomain ExchangeFreeBusy

Now, when the Directory Sync occurs, the Directory Connector will not only sync over Domino Users as Mail-Enabled Contacts in Exchange, but it will also gather Free/Busy information for the users in which the Free Busy Connector stamped as Domino objects as explained earlier.

On the Mail Information Tab, we will will want to specify the server that hosts ExchangecalCon.  You will also want to specify the Gateway mail file name.  This doesn’t necessarily have to be It can be  The Domino Administrator will know what the mail file name is.

On the Calendar Information tab, we will want to specify the server that hosts ExchangeCalCon.  ExchangeCalCon is one of the components from the Transporter Suite that is installed on a Domino Server which the Free Busy Connector on our Transporter Server will be talking to.  The Calendar system name can be anything you want.  I decided to name it ExchFreeBusy.

The notes.ini on this Calendar Server in which you specify in the Calendar server name must have its Notes.ini modified so that you can tell it to launch the ExchangeCalCon.  You will see a variable in the notes.ini called ServerTasks.  The important part in here is to add the following:

Excalcon ExchangeServerThatHostsFreeBusyConnector CalendarSystem

So let’s say our Transporter Server’s name is Shud-EXC01 and we set the Calendar System above to ExchFreeBusy, we would set this part in the Notes.ini to be:

Excalcon Shud-EXC01 ExchFreeBusy

Sometimes, instead of specifying the Calendar System in the Notes.ini, you will want to specify the Mail File Name we specified earlier instead of the Calendar System name.  In our example, we used Mail1.Box.  This is largely dependent on your version of Notes.  Typically, use the Calendar System name and if that doesn’t work, then try the Mail File name. The following information is taken from the Transporter Suite documentation.

Some versions of the Lotus Notes client will always send Notes RTF meeting requests to the first participant of a meeting. Notes routing then attempts to deliver this RTF message to a database with the same name as the Calendar System on the Calendar Server.
Setting this to “” causes the message to be delivered to the default Mail Router mailbox, the message is converted and delivered correctly.

Additional Configuration

There are some additional configuration steps needed to ensure our Free/Busy works.


If the Notes client was not installed in Single User Mode, run the following command:

Set-DominoFreeBusyConnector –Identity ‘Identity of connector’  -NotesINIFile “path_to_Notes.ini”


You will want to ensure that CalCon is started for every server in which users do Free/Busy lookups on the Domino side.  The reason why is that when a request from a Notes client does a lookup for an Exchange user, the CalCon task on its home server will use the Notes API and contact the ExchangeCalCon which then knows how to route the request over to Exchange.  The end result is that the Notes client will see an Exchange user’s Free/Busy data.

In our migration, we are utilizing Quest Notes Migrator to Exchange.  Because of this, we only have one way Directory Sync running.  In order for the process to work, we need to modify the personal document of Domino users to contain the text ExchangeFreeBusy when that user is migrated.  This is how the CalCon process finds the ExchangeCalCon process in order to route to Exchange.  Because of this, when you migrate a user via Quest Notes Migrator for Exchange, one of the options you must enter is the Calendar Domain that we specified above.

As stated earlier, the Directory Connector uses the Foreign Domain to find the Free Busy Domain Document’s domain name to pull free busy data.  Similarly, the CalCon process will find the ExCalCon Process by using the Calendar Domain specified in their personal document.  This is why the Quest sets the Calendar Domain in a user’s personal document when that specific user is migrated.

Internet Explorer Trusted Sites

We ran into several availability service errors (4003 and 4004).  Taking a look at the 4004 error, we can see that the Availability Service cannot find a public folder server for our Exchange 2007 Administrative Group.  This is not right as we clearly have a public folder server for our Exchange 2007 Administrative Group.  In fact, we have two.  This had us scratching our head and required a call to Microsoft PSS.  What they had us do is add all FQDNs for our Availability Service to each CAS Server’s Trusted Sites list in Internet Explorer.  Sounds crazy, but it worked and I didn’t see it documented anywhere.

To find out what FQDNs we need to add, run the following command:

Get-WebServicesVirtualDirectory | FL Name,Server,InternalURL,ExternalURL

So taking a look at our InternalURL, we have an FQDN of  Because of this, we will want to add to all CAS Server’s Trusted Sites list in Internet Explorer.  In the case of our production environment, we had several CAS Servers that had the same ExternalURL but every InternalURL was different as it pointed to the FQDN of the Server in which each certificate did have an entry for both and the FQDN of the server.

So let’s say we had 2 CAS Servers:


  • InternalURL –
  • ExternalURL –


  • InternalURL –
  • ExternalURL –

On the Trusted Sites List for SHUD-EXC1, we will add the following FQDNs to the Trusted Sites list:


On the Trusted Sites List for SHUD-EXC2, we will add the following FQDNs to the Trusted Sites list:


As you can see, the FQDNs are the same.  So it’s important that you add all FQDNs for all servers to each server’s Trusted Sites list.  You can find guidance on how to add FQDNs to the Trusted Sites list here.

100+ Public Folder Databases/Administrative Groups

If you have more than one hundred administrative groups and 100 public folder databases in Exchange, you will need to modify your Client Access Servers so the Availability Service can properly search through all 100 public folder databases.  It consists of modifying the Web.config file located on your Client Access Server and adding the following element:

<add key=”MaximumDatabasesInQuery” value=”250″ />

More instructions for this can be found here.


22 Responses to “Exchange 2007 and Domino Free/Busy Coexistence”

  1. on 24 Feb 2009 at 10:37 amTrevor

    One issue we ran into during our migration (Notes 6.5 to Exchange 2007) is that the CalCon process on Domino wouldn’t return free/busy information for users who were recently migrated using Quest’s Notes Migrator for Exchange. After about of month of working with Microsoft PSS, we figured out a workaround…

    Quest’s tool uses the “Other” setting for mail system when it sets forwarding for person documents. With this type of form, the CalCon process requires the full “Other address” (aka – forwarding email address) to be part of the “User name” field. In addition, we had to make the forwarding address + @domain (e.g.: the first name listed in the “User name” field before F/B requests were processed correctly.

  2. on 25 Feb 2009 at 9:41 amPerry Hiltz

    Elan, Great article.

    Unfortunately when organizations are executing a significantly large migration from Domino to Exchange, there are a tremendous number of fidelity issues related to the implementation of iCal between Domino and Exchange utilizing only the transporter. As you are already aware messaging utilizing the transporter suite along and certain migration products do not provide full ability to reply to messages once migrated.

    In addition these large organizations that require significant coexistence between the two platforms see significant issues with respect to the conversion of inline images, meeting invitations, and even embedded Domino objects such as embedded forms, buttons, and even encrypted mail.

    Each of these can lead to a significant number of help desk calls, user problems and perceived failure. I’d love to discuss this with you sometime.

  3. on 27 Feb 2009 at 1:04 pmsubject: exchange

    Weekend reading…

    When to use Move Mailbox Wizard or ExMerge to move Exchange mailboxes Exchange 2007 SP1 Features with…

  4. on 12 May 2009 at 3:47 amBuster

    Could you clarify what you meant with public folders on CCR-cluster and problems that you saw?

  5. on 12 May 2009 at 10:46 amElan Shudnow

    The problems were primarily related to the thing we had to do with adding the CAS fQDNs to Internet Sites. But either way, you are not supposed to host public folders on a CCR if you have “more than one” public folder database in your entire Exchange organization. You can check the CCR documentation on public folder support for more information.

  6. on 03 Jun 2009 at 2:13 pmJose Osorio

    Hi Elan,

    Our Company is migratin from lotus Domino 8.0 to Exchange 2007.

    Free/Busy works Fine, but i have this issue:

    Domino users From Lotus Notes Client and Domino Web Access can view Free/Busy information of Exchange Users.

    Exchange Users only from OWA can view Free/Busy information of Domino Users. Exchange Users from Outlook client 2003/2007 can´t view Free/Busy information from Domino Users.

    Do you know why Outlook clients can´t do that?



  7. on 04 Jun 2009 at 10:02 amElan Shudnow

    OWA 2007 uses the Availability Service to pull Free/Busy information but through a different API than Outlook 2007 uses. Outlook 2007 uses Availability Service as well, but again, uses a different API than OWA uses. Outook 2003 doesn’t use the availability service but goes directly to public folders.

    Seems a bit odd that OWA would work but not anything else. Can’t think of anything off the top of my head, but I’ll reply back if I do. If you figure it out, please comment with what you’ve discovered. Will be much appreciated.

  8. on 07 Aug 2009 at 6:29 pmKushal

    We recently installed Microsoft transporter suite for co-existence between domino, exchange 2003 and exchange 2007 users. As per one of the consultant we installed the calcon on a server with 2 domino partitions. One of the calcon is for exchange 2003 version and renamed it to excalcon2k3, since they both need to be in the same domino program directory. Each of the domino servers are running calcon and connecting to two different exchange servers (one to 2003 and the other to 2007). But when a notes client submits free busy request for exchange 2003 users, the request is actually going to the domino server which is connected to exchange 2007 server and the request fails. We tried recreating the foreign domain documents , restarted all the services and it worked for a while and started failing again.

    Has anyone tried running 2 calcon processes on a a partitioned domino server and if so, was there any work around.

  9. on 07 May 2010 at 8:01 pmJim

    Does anyone know if the Transporter Suite is supported with Domino 8.5 servers? I have seen several posts questioning this but none are definitive.

    We have Domino 8.5 with Transporter and the Directory sync works both ways. Exchange users can see Free Busy for Domino users. However, Free Busy from Domino 8.5 to Exchange 2007 is not working. The Excalcon gets this error when it is loaded on the Domino 8.5 server: "Warning: Exchange Calendar Connector failed to connect to <FQFN of Exchange server running Connector> with error code 5. Please ensure that the Microsoft Exchange Free Busy Connector for Lotus Domino service is running. Another connection attempt will be made on the next free/busy request." No matter what we try it will not work, then I saw several postings stating 8.5 is not supported by MS. Any help?

  10. on 14 May 2010 at 5:12 amLouise

    Microsoft informed me that the Transporter Suite is not supported with Lotus Domino 8.5 (I think up to 8.0.2 is). I have directory syncing (after some configuration changes in the .tbl files) and free/busy working between Domino 8.5.1 and Exchange 2007. Do you have Microsoft Exchange Server MAPI Client and Collaboration Data Objects 1.2.1 installed? If not, then the free/busy connector will not connect. I do have issues with the Scheduler being up to date for Lotus Notes users for Meeting Rooms located in Exchange. I have to open the Outlook client using the /cleanfreebusy switch to force the free/busy info to be pushed to the Exchange server so if you know how to get around this then let me know. :)

  11. on 14 May 2010 at 5:14 amLouise

    I mean "I do have issues with the Scheduler NOT being up to date for Lotus Notes users for Meeting Rooms located in Exchange."

  12. on 07 Jun 2010 at 5:29 amdavid

    Hi Louise
    Are you able to shed any light one how you got the free busy stuff working as i cant install exclon on the domino server because it says domino is not installed? Also is your free busy working in both directions?

  13. on 07 Jun 2010 at 5:32 amDavid

    I am using Domino 8.5.1.

  14. on 09 Jun 2011 at 12:22 amNathan

    Hi David – did you find a fix for this problem? I've got exactly the same thing now and am going out of my mind!! Any help would be great! Thanks Nath

  15. on 29 Jul 2011 at 12:40 pmMichelle

    We figured out that the problem was because we were runnining Windows 2008 R2. The install was successful on a Windows 2003 R2 SP2 box with Domino 8.5.2

  16. on 08 Aug 2011 at 8:22 amMichelle

    Update – It appears that the issue was the Domino 8.5.2 64 bit server install.

  17. on 23 Jun 2010 at 8:31 amVinod

    Can i Migrate only Calender & task inofrmation from lotus to exchange by using Microsoft Transporter Suite

  18. on 19 Jul 2010 at 11:21 amDhamm

    I have configured the FreeBusy connector with Domino 8.0 and Exchange 2007.
    Domino is running on Linux, but I installed another Domino server on Windows server only FreeBusy
    Directory synching works fine with Linux servers but Free/busy is not working.
    I am using same internet email domain sharing between Lotus and Exchange.
    There are no errors in event logs and Domino loading of Excalcon gives no error but a success and also at the Exchange end.
    Don't know what to do.

  19. on 08 Oct 2010 at 4:23 amChris

    We need to connect an exchange and domino environment between two separate business units in different network ranges (equivalent to connection e and n in the graphic under "Additional Configuration").

    As far as I was able to find out, those connections are realised via NRPC and Mapi. What are the alternatives? Can you wrap those protocols into an HTTP/SSL Layer? Are they proxy-capable? What's the most workable solution connecting two separate networks?


  20. […] Also Elan Shudnow wrote a nice article regarding Free/Busy, a little bit more deep-dive into it and how it works, it can be found here. […]

  21. on 28 Oct 2011 at 12:00 pmJohn

    Hello, My intent is to run MS Transporter Suite on a Hub transport Role and only configure the Free/Busy Connector. I have 2007/2003 Clients.

    1. Will the MS Transporter update both Public Folder Free/Busy Folders and the Availability Service?

  22. on 02 Nov 2011 at 7:51 pmElan Shudnow

    Well one of the MS Transporter's job is to pull in Free/Busy. So yes.

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