Question on Set-OutlookProvider EXPR

Question

Hello,

I accidentally found this article:

To ensure Outlook Anywhere connectivity after a database, server, or datacenter switchover, you must use the same Certificate Principal Name on each certificate, and configure the Outlook Provider Configuration object in Active Directory with the same Principal Name in Microsoft-Standard Form (msstd). For example, if you use a Certificate Principal Name of mail.contoso.com, you would configure the attribute as follows.
Set-OutlookProvider EXPR -CertPrincipalName "msstd:mail.contoso.com"

...and got confused a bit: I don't quite understand what does this command do - the Set-OutlookProvider documentation page says nothing about EXPR parameter. Furthermore, as soon as the Set-OutlookProvider cmdlet creates the new Autodiscovery service settings does it mean Q1) that the usage of Set-OutlookProvider EXPR -CertPrincipalName "msstd:mail.contoso.com**" is mandatory and the default set of Autodiscovery service parameters is not enough to service multi-datacenter configurations?

Q2) Should I issue Set-OutlookProvider EXPR -CertPrincipalName "msstd:*.contoso.com if I'm using wildcard certificate? ...I've never run that command before but had no issues with using wildcard certificates....

Thank you in advance,
Michael

Answer 1

Hi,

Outlookprovider EXPR is used for outlook anywhere protocol and with scenarios having multiple AD sites with internet facing Exchange servers, wildcard certificates, etc. Legacy versions of Exchange/Outlook will look for these values to connect to the Exchange using Outlook Anywhere.
Please refer the below articles for more information,
https://techcommunity.microsoft.com/t5/exchange-team-blog/the-autodiscover-service-and-outlook-providers-how-does-this/ba-p/584403
https://techcommunity.microsoft.com/t5/exchange-team-blog/when-if-and-how-do-you-modify-outlook-providers/ba-p/603426

Answer 2

1. I don't think it's mandatory, it's more likely to be a (best-practice) suggestion, or solution when your Outlook clients meeting connectivity issues and you get error like this in EXRCA:
2. Yes.

Set-OutlookProvider -Identity EXPR -CertPrincipalName msstd:*.contoso.com
Found this from old blog: https://learn.microsoft.com/en-us/previous-versions/office/exchange-server-2007/cc535023(v=exchg.80)?redirectedfrom=MSDN

---

If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.