After upgrading from Exchange 2003 to 2010, users have outlook certificate continues error

Hello everyone,

I have upgraded a client's exchange 2003 to 2010 and now outlook users receive Certificate error message every time they open Outlook 2007.

the client is not using public certificate and they are not intending to deploy one anytime soon. but there's about 1000 users who are domain joined and they have the Certification Authority certificate installed properly.

One thing I did notice which is when I create a new Outlook profile for any user, I get the Certificate warning just once and then next time it disappear.

but with the old account no matter how many times I accept the Certificate warning, if I close it and open outlook again i'll get the warning.

Is there anyway to do something to fix this without needing to manually go to those 1000 PCs and fix it?

LVL 24
Mohammed HamadaSenior IT ConsultantAsked:
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Simon Butler (Sembee)Connect With a Mentor ConsultantCommented:
You need to get the SSL prompt, then look at the certificate and see what it is connecting to.
Then find the host name that is configured incorrectly and correct it.

Although for a 1000 user platform, I cannot believe they are not using a trusted SSL certificate. Is there NO OWA access, ActiveSync or any kind of remote access? When a suitable SSL certificate is less than $60/year (less than the cost of a CAL for Exchange and Windows) it really doesn't make any sense to not do it.

Alex Green3rd Line Server SupportCommented:
Sounds like an autodiscover issue

Run through that, i'm sure the autoconfig isn't going to work properly
Mohammed HamadaSenior IT ConsultantAuthor Commented:
Hi Alexgreen

The article says that autodiscover service could cause the issues listed below which I have none of them currently. the only problem I have is the non-trusted certificate warning.

As I said if I configured a new profile within outlook, the users will receive a warning just one time and then it wont show up again.

So I'm suspecting a problem with the old Outlook profile/cache thing to do with maybe?

Problems with Autodiscover service or how it’s configured can causes issues such as:

Cannot view free/busy information.
Cannot download Offline Address Book (OAB) / receive error code: 0x8004010F.
The Out Of Office assistant is not working.
Prompt for a user name and password during the Autodiscover process.
Outlook anywhere stop working.
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Alex Green3rd Line Server SupportCommented:
Since you migrated them from one server to another it will use the autodiscover feature to configure their outlook clients when you initially move them over. Which would mean that it would have to use the certificate to start the process.
Mohammed HamadaSenior IT ConsultantAuthor Commented:
HI Simon,

Yes, I didn't believe that as well! they said they can get it but due to bureaucracy in the procedure it might take up to a month or two to pass the purchase order.

regardless, I have find out the issue! the problem was that the Internal FQDN of the Exchange 2010 server was not included in the certificate SAN and therefore it was giving the error.

I have created another new cert that's not wildcard and included all the possible FQDN for the servers that I could think of.

The customer is using 2 different Domain names. the internal domain is different from the external one.

Now after I imported the cert and assigned it to the services, I seem to have a problem with the OWA when viewing the Calendar, Contacts, Task or Public Folders.

An unexpected error occurred and your request couldn't be handled

on Outlook desktop client . this issue doesn't occur! I can view the calendar, Tasks, Public Folders, global address list without any issue.

I have moved the OAB and updated the mail policy. could this be related to them not to the certificate?
I am attaching a snapshot of the error.
Please update Exchange  CAS server with latest Rollup
Mohammed HamadaSenior IT ConsultantAuthor Commented:
I solved the problem by turning off the OWA redirection on IIS, and yes it seems that i'm on a very old version of SP1. I will upgrade to SP2 today and see what happens.
Simon Butler (Sembee)ConsultantCommented:
Skip SP2 and go straight to SP3 with the latest rollup.

Mohammed HamadaSenior IT ConsultantAuthor Commented:
I just have one more question, after migrating about 500 users successfully and among them some who had errors but I choose to skip those errors.

Some of those users kept getting prompted to enter their username and password on outlook 2007! I tried everything possible to get rid of this error but it seems it might be related to the user's outlook profile getting corrupted maybe?

When I try to create a new outlook profile with another user the autodiscover worked. but when I tested the same user it didn't work even though I tried it on the same PC.

Could this be related to the errors skipped while migrating?
Mohammed HamadaSenior IT ConsultantAuthor Commented:
You're right Simon, the certificate had something wrong in it. I was using a wildcard certificate which had only the Public domain name of Exchange. but Customer had migrated their old domain to a new domain and internally they are using a different domain.

After looking closely at the Certificate, the Exchange server's FQDN was not included in the certificate which caused users to get warning.

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