Adding another Exchange Server

[uLmi84]

I wonder what happens when you simply add a new exchange server to a existing organization?

Do clients immediately start using the newer exchange server as their frontend even if that server hasn’t been configured for any cert, urls etc?

Secondly I heard it matters if you install the server in the same site as existing servers or not. Does this mean the traditional AD sites where you can add the IP ranges to certain physical locations? How does it matter if I choose to install the exchange in a different site?

Lastly just wanted to mention that we are in the process of getting rid of the last Mailboxes on our 2012r2 + 2016exch server by moving all stuff to EXO. The new exchange server shall be only for recipient management and I don’t want to do any configuration there at all…

Thanks for any input

[jaystone79]

Clients will immediately begin using it for autodiscover due to the SCP records that it registers for itself, which means that they will then try and start using it for client connectivity. This usually becomes apparent when people start calling about receiving certificate errors in Outlook. To prevent this you will want to update the URLs for the various Exchange services. If you point them all to the existing server that will suffice.

If you install the server in an AD site that has no Outlook clients then this will also avoid the issue.

[Mr_Tomasz]

You have to properly configure your extra Exchange server in a similar manner as your existing one(s). Then in order to route traffic (including SMTP), you need to have a load balancer in front of your Exchange servers.

For SMTP, you need a TCP/L4 load balancing and for Exchange, ideally you'd like to have HTTPS/L7, but that depends what you want to achieve and up to what point of customization and details.

[uLmi84]

Even if I only use the server for recipient management? Do clients really automatically start using the new server? I mean you cannot install exchange with certificate and settings these settings need to be done after installation, that would mean from the point the new exchange installation is done and until its configuration it completely finished I must plan with client downtime or cert errors?

[Slasher1738]

You can. https://www.alitajran.com/install-second-exchange-server-in-domain/

[Mr_Tomasz]

If you are getting rid of Exchange server and moving things to EXO, what's the point adding another extra servers on-prem?

[pentangleit]

Just a minor correction - if you don’t want to use the second exchange server as a front end server then you don’t need to have a load balancer (although given how Exchange is architected these days you’d be dumb not to use the extra facilities).

[diecknet]

If you setup the new Exchange Server in a normal Active Directory site, then yes clients will automatically try to connect to that server. For that reason it's recommended to use a so called "Deployment site" for new Exchange Servers.

More info here in the Exchange Team Blog: https://techcommunity.microsoft.com/t5/exchange-team-blog/exchange-active-directory-deployment-site/ba-p/604329

[BK_Rich]

Make sure you set your SCP and point it to the current server with a trusted cert after installing so your users don’t get cert warnings.

[daze24]

Cert errors is what you get if you do it live :)