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Email poetry, what a great thing to see floating around on the blogosphere. This does make one think of the constant ebb and flow of peoples desires and the truth. As the author points out people think email is antiquated and yet depend on it furiously for business purposes. They desire something better, but it’s hard to find an office without some mail client running.


Slow Calendar Retrival between cross forest organizations

We’ve been piloting Exchange Online in a hybrid mode with our Exchange 2010 SP3 exchange deployment. Initially we were having some issues with calendaring sharing and free/busy lookups between organizations. Users would try to lookup someone’s availability and would sporadically get timeouts and fails. Users would have to refresh several times before the information would finally pull back.   The issue was happening in both directions (from on prem to cloud / from cloud to on prem) in Outlook (2010/2013) and in OWA.

We logged a case with Office 365 and began the fun process of troubleshooting the issue. Finally we discovered what the issue was. 

When the hybrid wizard is run you get two new organizational relationships created, one on premises and one in Exchange Online. These can be viewed by performing a get-organizationrelationship in Powershell in the Exchange Shell on premise or in a Remote Powershell session established with Exchange Online. Both relationships get the TargetApplicaitonUri and the target AutodiscoverEpr populated as part of the process and the “On Premises to Exchange Online Organization Relationship” will get the TargetOwaURL by default as well.

The TargetSharingEpr field is left blank and herein lies the source of the availability lookup fails. What we had to do is use PowerShell in both organizations to set the TargetSharingEpr with the correct values.

PowerShell commands:

This will setup the Target sharing EPR for your on premise organization relationship and needs to be run against your local Exchange.

 Set-OrganizationRelationship “On Premises to Exchange Online Organization Relationship” -TargetSharingEpr “

This will setup the Target sharing EPR for your Exchange Online organization relationship and needs to be run in a Remote PowerShell session established with Exchange Online.

Set-OrganizationRelationship “Exchange Online to on premises Organization Relationship” -TargetSharingEpr “


Exchange On Premise Organization Relationship:


Exchange Online Organization Relationship:


Instantly after making these changes we were able to perform calendar lookups and use the scheduling assistant with 100% reliability across premises.


EHLO World

I guess the appropriate thing to do is start with an introduction. My name is Brian Reese, I’m the Systems Analyst responsible for Exchange and ultimately all things email for a mid to large size Exchange Organization (> 20K mailbox objects) for a company with global operations. I’ve been working on Exchange for years, starting on Exchange 2007. We have since upgraded to Exchange 2010 and setup hybrid with Exchange Online as the company explores what Office 365 can bring to the table. I’m a big advocate for PowerShell and have even been awarded a sign created by my colleagues stating that I’m the ‘PowerShell Support Center’ for the company.

My hopes for this blog are simple and will evolve over time I’m sure. I would like to share some of my experiences and hopefully provide some light in a dark world. I’ve have no previous experience with blogging so this will be brand new for me.

God Speed Everyone. Here we go.