Exchange certificate error/setup

OK, I am pretty new to exchange, and I hate certificates.  Not a total newb but don't skip the obvious please.  Additionally, I am picking up this system from old admins that left on bad terms.

The core problem is this.  On setting up a new user on a new computer, I receive a certificate error.  I can skip it and it will run through, but my users freak out, and I do not want to teach them to ignore these warnings, so I need to get it fixed.

The Error is
Cert Error
The certificate is
From this, it appears that the is using a self signed cert, and is also SHA1.

The environment is like this
The Root CA does not have a website I can download the root cert from (broken?)
The Sub CA does and appears to be working

There are a bunch of certificates on all 3 exchange mail servers, most all are self signed I THINK  

Only listing the certs in the exchange MMC IIS console;
There ones listed in the web admin page are similar, only excluding the one that is expired.

There are so many, few to none match.  No rhyme or reason.  

I THINK I need to add a good cert from the Sub CA, and then remove the bad certs.  But this is a production box, and I am worried about removing certs that haven't expired, bad past experiences.

I guess I am asking for some guidance in cleaning up this mess.
LVL 11
Lofty WormIT ManagerAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Scott CSenior EngineerCommented:
Get a cert from a CA....GoDaddy is a good one.  They also have excellent instructions on how to install.

You need a trusted cert from a CA.

The command you want to run is Get-ExchangeCertificate | fl > c:\cert\cert.txt

Make sure you have a folder called "cert" on your C drive.

Get the trusted cert, install it, and this should take care of your issues.

Be sure to get a SAN cert with the names you,,, etc.

When you run the command I gave, you will be able to tell which ones are self-signed very easily.
Lofty WormIT ManagerAuthor Commented:
What if I want to use my own CA.  People can't access there work email from outside the office
Scott CSenior EngineerCommented:
You can use your own CA.  That's fine.  Verisign is another one.  Just make sure they are reputable and provide good instructions for installing the cert they sell you in Exchange.
Ensure Business Longevity with As-A-Service

Using the as-a-service approach for your business model allows you to grow your revenue stream with new practice areas, without forcing you to part ways with existing clients just because they don’t fit the mold of your new service offerings.

Scott CSenior EngineerCommented:
Once you have a valid cert installed from the CA, your users will be able to access their email from outside of the office.
Lofty WormIT ManagerAuthor Commented:
But my CA is not trusted by the world.
Lofty WormIT ManagerAuthor Commented:
Do I need a separate cert for all three servers, a wildcard cert, or one cert with three names.  What are the names?  It appears that I need the servername(3), clustername(1), WMSVC (3), and autodiscovery(3). You can see where I am getting confused since there are so many :(
K BCommented:
View the certificate when you see the popup and look at the cert to see if it is valid .. .also look at the certification path tab.  

Are each one of those installed on each machine?

get-exchangecertificate -server XYZ | FT -auto

will show you which certificate (thumbprint) is assigned to Web (w) which is primarily the one we are dealing with here.

A cheap comodo certificate (with and  can make life so much easier.. you dont have to dole out certs to your clients.  You dont want your DNS for OWA and autodiscover (and the other vdirs) to point to server names but if you absolutely have to do that then include the names in a UCC/SAN cert... it's like $45 bucks

I use: 

you need the UCC/SAN certificate
K BCommented:
Scott CSenior EngineerCommented:
A CA by default is trusted by the world.  That's why a CA is a Certificate Authority.

Run the above command I gave you, look at the results.  In there you should see the SANs you need to have put in your cert.

If your CA isn't trusted by the world, then you need to find one that is.  Verisign, GoDaddy, etc.

One cert installed on each server, you don't need one for each machine.

A wildcard cert will work but that can have its own configuration challenges.
Lofty WormIT ManagerAuthor Commented:
OK, I am ready to start pushing buttons, but I am nervous about this, as I have little xp with exchange.  I have no fear of running the PS commands, but How can I "quiesce " one of the servers so as not to impact it?  Also, how can I connect to 1 of them specifically to see if my fix works??
Scott CSenior EngineerCommented:
Installing a cert from GoDaddy is easy.  Just follow their directions.

How did things go?
Lofty WormIT ManagerAuthor Commented:
I called MS.  I am getting a walk through.  there are some problems with SHA1, Domain smart card, and the cert now needs to be public, not local.  I will try and post my resolution at the end

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Lofty WormIT ManagerAuthor Commented:
So I called MS, and there was a LOT of command line and cert clean up, to much to mention.  My one take away from this was that exchange certificates are at hart just IIS certs, attached to exchange services via command.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.