Exchange Server 2019 Public Preview

We’re pleased to announce a preview build of Exchange Server 2019 is now available (download removed as Exchange 2019 is now released).

We strongly believe Office 365 delivers the best and most cost-effective experience to our customers, but we understand that some customers have reasons to remain on-premises. Exchange Server 2019 is designed to deliver security, performance, and improved administration and management capabilities. These are the attributes our largest on-premises customers tell us they need from Exchange. We also have features end-users will love too of course.

Here are some of the key features in each of these areas:

Security: We’ve included support for installing Exchange Server 2019 onto Windows Server Core. Exchange Server 2019 installed on Windows Server 2019 Core provides the most secure platform for Exchange. You also have the option of installing the Exchange 2019 Preview onto Windows Server 2016 Core or Windows Server 2016/2019 with Desktop Experience, but we have worked hard to make sure running Exchange on Windows Server Core 2019 is the best choice for our code.

Performance: We’ve done work to allow Exchange Server to take advantage of the larger core and memory packed systems our customers buy these days. We’re confident you can be very successful running Exchange Server with up to 48 processor cores and 256GB of RAM.

We’ve re-engineered search using Bing technology to make it even faster and provide better results, and in doing so have made database failovers much faster, and administration easier.  The search indexes are now within the database itself. There are no more separate log files to manage. As the index data is now within the database, normal log shipping includes the database and search data in a single replication and the index is always up to date on all database copies.

At Ignite last year, we told you that Exchange Online had started using Solid State Drives. Yes, SSD’s. Many people were shocked at this.  For years we’ve been telling you to use cheap low-cost storage, and then we switched and started using SSD? What’s up with that Exchange team?

Well, that isn’t exactly what we said, what we said was we were using SSD’s in addition to cheap low-cost spinning disks. Why? Well we’ve pretty much reached the limits of what we can do with cheap storage, read latency in those disks hasn’t really improved yet storage capacity just keeps getting larger. It led us to conclude we needed to re-think our strategy. And we did, and the short version is that we store some of the data from those spinning disks on the SSD, and we use that super-fast device to store key search data, to make logins faster, and message retrieval faster. We still use low-cost storage for storing all of data but intelligently use SSD’s to make the overall user experience better.

We’re adding this tiered storage read/write capability to Exchange Server 2019 but it’s not enabled in the Preview build. We know you will all have lots of questions about this new feature and we will of course have planning and configuration guidance available when we ship, but we will be talking a lot more about these changes at Microsoft Ignite 2018. You are going, aren’t you? We are.

End user experience: One of the most important capabilities in Exchange is calendaring. All large enterprises are heavy calendar users and those organizations rely on calendars to help people get their work done. We’re bringing a few key features such as Do Not Forward and Simplified Calendar Sharing from Office 365 to On-Premises Exchange. We’re sure a lot of end users will be very happy with those features. Administrators get some new calendaring features too, as we’re adding the ability for admins to manage events on user’s calendars and to assign delegate permissions more easily.

One thing to note is that Unified Messaging role will not be available in Exchange Server 2019. Customers who currently connect either a 3rd party PBX or Skype for Business Server to Exchange Server won’t be able to do so with Exchange Server 2019 mailboxes. Those customers considering an upgrade to Exchange Server 2019 should consider migrating to Skype for Business Server 2019 and using Cloud Voicemail, or migrating to Office 365 with Cloud Voicemail. More information on this change will be available prior to launch.

That’s a brief roundup of many of the changes we have baked into Exchange Server 2019.

We plan on launching Exchange Server 2019 later this year, and we’re planning on talking about it a lot more at Microsoft Ignite.

Take a look at the Preview, and we really suggest you install it on Windows Server Core, and Windows Server 2019 Core if you have access to that. We will be publishing a blog post with tips for running Exchange on Server Core in a few days.

But please remember it’s not a production release, so please don’t install into production at all.

We look forward to your feedback, and in case we didn’t say it enough times, we’ll see you at Microsoft Ignite!

The Exchange Team.

Comments (82)
  1. Gabriel Amorim says:

    Hey guys!
    I installed Exchange 2019 on my lab environment and I saw that I still having a Content Index files inside mailbox folder. Can you explain more about this feature?
    Anyways, good job!

    1. Hello Gabriel,

      Thanks for taking a look at our preview. Yes, we are aware that there are still content index files being generated. Rest assured the actual indexes for your data are actually in the mailbox database. We still have a bit of clean up to do before we release later this year. The work item to stop creating these is actually in active development and was not completed before we cut the preview build.

  2. Rob Helm says:

    What’s the plan for Exchange Online Unified Messaging? It sounds like it will be eliminated completely in favor of Cloud Voicemail. If so, what is the timeframe for the transition?

    1. Hi Rob, we are only announcing this change for Exchange Server 2019 On-Premises today.

  3. Peter Vassiliou says:

    What about the Edge Server role? Will it be available in the future or is it going to be discontinued?

    1. @Peter – yes, Edge Role is available in Exchange Server 2019

  4. Sathiesh S says:

    The download link is not working. Link:

    1. Sorry about that, we’re working on it. Clearly the demand caught the download people by surprise. ;-)

  5. harm says:

    as the final release will made public, can we run exchange 2013 in co exsistence and migrate?

    1. @harm, yes you will be able coexist with Exchange 2013.

  6. John says:

    Thank you for the post. Is there a possibility you can elaborate on your statement “One thing to note is that Unified Messaging role will not be available in Exchange Server 2019”? We still rely heavily on our on our Premise Exchange with Unified Messaging. From the reading I have done today even with Skype for Business, “you must upgrade to Cloud Voicemail if you are using Exchange Server 2019”. Any further insight is appreciated, we do have staff attending Microsoft Ignite 2018, but this could really impact our organization. Appreciate the Blog always.



    1. John, you might want to take a look at the pre-release documentation on configuring Skype for Business Server 2019 –

  7. EsKay says:

    Looking at the graphic, it appears that installing this version may lead to spontaneous outbreaks of St Vitus’ Dance.

    1. It might. Wouldn’t that be something.

  8. calendaring says:

    this is excellent. One of the most common things that users say when I ask them what they mostly do is “calendaring”

    1. with a name like yours are you sure they aren’t just trying to get your attention?

  9. S. Omar says:

    How about mailbox encryption?

    1. We’re not announcing everything in 2019 today, just teasing some of it. Come to Ignite and find out more.

  10. Michael Vi says:

    Thanks MS Exchange team.

    Gonna have fun tonight.

  11. Christian Schindler says:

    Wohooo! Finally! Looking forward to installing and testing the bits… Server Core Support is very much appreciated! Cheers Christian

    1. Great to hear the positive reaction to Server Core support. Thanks Christian!

    2. Christian,

      This feature is near and dear to my heart and I am happy to hear you are excited about it too. The experience on Windows Server 2019 Server Core truly is the best. I hope you have access to those builds and can give it a try.

  12. neil donaldson says:

    “We strongly believe Office 365 delivers the best and most cost-effective experience to our customers, but we understand that some customers have reasons to remain on-premises.”
    Can you share any information on the solution that will allow the removal of the last exchange on premise server in hybrid mode using ad sync ? What are all the customer with an “admin” exchange 2013 box going to do , once exchange 2013 is EOL ? thanks

    1. That problem exists for all versions, and we’ll fix it for all versions. More at Ignite on that.

  13. Dmitry Alferov says:

    Goodbye Update-MailboxDatabaseCopy -CatalogOnly ?

    1. Dmitry, that property will server no purpose on Exchange Server 2019, but we plan to leave that for backwards compatibility when managing Exchange Server 2016.

  14. Christian Schindler says:

    Wohoo! Finally! Just one question: I tried to install the bits on a Windows Server 2016 Core machine and the Installation Fails with “This computer requires the Microsoft Unified Communications Managed API 4.0”. But of Course this can’t be installed on a Server Core Installation because it is missing some components required by UCMA. Is this a know issue or is there a Workaround? Thanks! Cheers Christian

    1. Christian, on Server Core you can install the UCMA of the Exchange 2019 ISO, it’s in the UCMARedist folder.

  15. BTW97 says:

    I’m very disappointed to hear that you’re removing UM from Exchange 2019 and I hope that you’ll reconsider that decision. Or at the very least, allow for some sort of compatibility mode where mailboxes on Exchange 2019 can continue to be UM enabled as long as an Exchange 2016 server remains in the mix to handle the SIP trunks, etc.
    The suggestion to use Cloud Voicemail as a replacement is not reasonable. First, if I’m still using on-prem Exchange its because I have various political and/or technical reasons why a cloud service doesn’t work for my organization. So telling me to use a cloud service to replace functionality stripped out of my on-prem server just doesn’t make any sense – if I could use the cloud, I’d be using the cloud. Second, even if I could clear the political and technical hurdles to using Cloud Voicemail, it’s not even just a “drop-in” service. I also have to go deploy Skype for Business and (if I’m understanding the documentation right) toss out my IP-PBX. I hope I’m wrong about that, because there is no way I could get support for such a migration.
    So, what should have been a straightforward upgrade/migration to Exchange 2019 during our next hardware refresh now becomes much more complicated and expensive since I’ll have to purchase an on-prem voicemail system.

    1. We appreciate this might be tough for some customers, and respect your position. I will say, you don’t have to upgrade to 2019 the moment it arrives, or at all. We’re not changing anything with regard to UM in earlier versions, they will be on working while you figure out your longer term plan.

      1. Richard B Rocks says:

        This decision is yet another HORRIBLE one from the Microsoft Exchange team. Leave it to the Exchange team to remove functionality that has been in Exchange for many versions and to spring that on us at the end of a development cycle and tell us that we need to switch to their cloud offering and essentially rip and replace our existing systems, which weren’t cheap, to align with what they think everyone on the planet should be doing. I’ve been a huge supporter and user of Microsoft products for decades, but this is absolutely rediculous… How hard could it possibly be to LEAVE a feature in a product? This is as dumb as when they removed fax functionality for no reason and when they discontinued Forefront for Exchange, leaving EOP as the only truly viable alternative… Had it occurred to you people that support companies have built solutions around the functionality your products offer and you cause major issues for them every time you pull this crap? This makes the phone systems that my company set up for clients, integrating voicemail and auto attendant functionality with Exchange, unworkable as offered since part of the pitch was to have it all in a nicely integrated system, keeping up with the latest releases of Exchange and Office.. What ever happened to giving warning that a feature would be removed in the future by depricating it in the current version, so that integrators could at least know what’s going to happen and can account for it in their designs? Also, I realize you want everyone to go to the cloud, but that is never going to happen, and the more you do these things, the more loyal customers you’re going to push to other solutions. I realize that Azure is growing incredibly fast, but that doesn’t mean you should alienate yourselves from everyone else. You’re making it harder and harder for people to WANT to do business with you…

  16. Brad Barrier says:

    Love the dancing users. If this version does that I’m upgrading ASAP. : – )

    1. I just checked a test server I have, and I spontaneously danced. So I think it’s in the Preview. (Your own response may vary etc etc, lawyers made me say that etc etc)

  17. KatarinaT says:

    Thanks for the post and news about indexing within the db now!

  18. Since Gabriel noticed we still have a bit of cleanup to do, it is a preview after all, you will also notice that some remnants of Unified Messaging have yet to be removed. We are aware and actively putting the final DVD on a diet between now and RTM.

    1. So those dancing users will be even thinner come RTM.

  19. RobK_ says:

    Great Job!

    Can you let me know if the powershell -verbose switch is finally fixed and working as it should?


    1. We have worked with the PowerShell team and have been told this is resolved.

      1. RobK says:

        Sadly its still not working not even in the Core edition. How cruel can you be?

        1. robk says:

          I’m assuming that by not replying to this message you know that -verbose switch does nothing this will never be addressed either by your team or the OS team. Thanks for confirming it by being silent.

  20. Fred says:

    Will support coexist exchange 2010?

    1. No Fred, it will not. That’s consistent with previous versions supporting n-2 co-existence.

  21. Zoltan says:

    “We’ve re-engineered search using Bing technology” – My experience with Bing is that it can’t find stuff even on Microsoft’s own pages. It deeply concerns me to have it as THE search engine in Exchange.

    1. We’ve always used Microsoft technology in our search engine Zoltan, this is no different.

  22. GJ65 says:

    I ‘ve been truing for a few days now, but still get a corrupted download.

    1. Have you tried using a different browser? The team which runs our download center has investigated these reports and informed us the download center is functioning normally at this time. Some browser/OS combinations seem to be having difficulty processing the package due to its size. You may also try using the download manager (

      1. GJ65 says:

        Hi Brent,

        After a few tries on Win10/Edge without success I now downloaded the file on Win2016/IE without any problem.


  23. mcb says:

    Any hope of DKIM signing coming in one of the next builds? Office 365 has this feature, it would be logical to also have it natively in Exchange Server? Native support would be so much better than third-party DKIM addons which silently break after Exchange Server updates.

    1. Hello MCB, we have heard this request from multiple customers. We are evaluating if this can be added to Exchange Server 2019. At this time, there is no commitment to this feature.

  24. yacoobJG says:

    On Ignite 2017 when introducing Exchange 2019 you mentioned sth about “outsourcing authentication”. Is it available in preview version and if so – how?

    1. Hybrid Modern Authentication is available in Exchange Server 2016 and the Exchange Server 2019 preview. You can read more about this at,

  25. vilickgaby says:

    Hey Guys,
    Many Antispam Software/Tools (actually almost all of them) require to be installed on the Mailbox server, and require the GUI capabilities of the Server. How an Exchange 2019 installed on a Core-Server is going to deal with that ?
    is there an Upgrade on the Exchange2019 to support O365 Cloud protection ? or those third antispam Software should Support Server-Core ?
    thanks for your answers

    1. Thanks for asking this question. There is a common misconception that Server Core does not include a Graphical User Interface (GUI). It does. Server Core removes the Explorer shell and the UI extensions. That also means that MMC is not installed because it depends on Explorer Shell. GUI based Windows applications which don’t depend on Explorer or MMC continue to function normally on Server Core but may look a little different, e.g. Font usage. Even the graphical Exchange Server setup wizard runs normally on Server Core for example. What we tend to see is that the installer for some applications doesn’t function normally but the underlying application works normally. In those instances, installing the application using a “quiet mode” supported by the installer is often an available workaround. Our own Unified Communications Managed API (UCMA) is an example where the previously released installer doesn’t work correctly on Server Core but the underlying functionality works fine. This is why we have created a Server Core compliant redistribution package for this and placed it in the Exchange Server 2019 .ISO. If an application installer does not work correctly, we would expect ISV’s to make use of an installer that is compliant with Server Core. If the application requires Explorer or MMC, then additional work will be required by the ISV. Installing and running the management experience for these applications on a machine with the full Desktop Experience is also an option.

      That being said, Windows Server 2019 Server Core will include an optional Feature On Demand (FOD) component for Application Compatibility. This is intended to assist the Windows ecosystem in their product transition to support Server Core. It will install a supported version of MMC, as well as other components, which run on Server Core. The Exchange Team will not support use of the AppCompat FOD on servers where Exchange Server is installed. This is intended to be a transitional technology only and we have worked closely with Windows over the past two years to support Server Core natively in this release. The Server Core development team is aware of our plans in this regard and has expressed support for our approach.

      We believe that the transition to Server Core as the preferred operating system for Exchange Server is a journey that will improve over time as the ecosystem adapts to this change. It is one that will result in more secure servers by removing functionality not required by Exchange Server and be worth the effort.

      1. vilickgaby says:

        Thanks for your reply. These are good informations to consider.

  26. Timony says:

    Hi Ex Team

    would it be possible to migrate from Ex 2010?

    1. Not directly Timony. Exchange Server 2019 won’t install if 2010 is detected, so you’d need to install either 2013 or 2016 first, remove all Exchange 2010, then move to 2019.

      1. Timony says:

        Hi Greg,

        This is madness
        do I need to buy licences for 2016 and 2019 to migrate from 2010?
        Why can´t you support direct migration to 2019 as I don´t see any structural difference between 2016 and 2019.


        1. This isn’t new to Exchange, we’ve supported n-2 co-existence only the last few versions. It’s been 8 years since Exchange 2010 and we’ve released two major versions you could have upgraded to without hitting this issue.

          It’s possible your licensing terms might allow you to run 2016 anyway, you should contact the license re-seller, and if it’s all good, upgrade to 2016, then to 2019 if you want to.

  27. MrRoundRobin says:

    Hey guys,
    does Exchange 2019 support ECC certificates?

    1. Hello,

      Yes, we support Elliptic Curve Cryptography with Exchange Server and we actually are recommending this over non-ECC key exchange. Exchange doesn’t actually implement our own key exchange, hashing or cipher algorithm negotiations. We ride on top of and rely on the capabilities of the operating system. We believe this gives admins the greatest implementation flexibility and consistency. It allows Exchange to adopt new capabilities as soon as operating system support is available. We currently are able to support ECC all the way back to Exchange 2010 on Windows Server 2008 R2.

      1. MrRoundRobin says:

        Hi Brent,
        thanks for the quick reply. If I try to use a ECC Certificate I get following error:
        “The certificate with thumbprint was found but is not valid for use with Exchange Server (reason: KeyAlgorithmUnsupported).”
        See also:

      2. Roger says:

        Appreciate this is a tangent from the post itself, but are there any specific prerequisites for ECC encryption with Exchange Server? A client attempted to use ECC with Exchange Server 2013 as part of their hybrid deployment and ran into the same error the other poster mentioned. Fortunately they were happy to proceed with RSA but are in a process of moving all their internal CAs to ECC, so it’d be good to know for the future.

        1. Roger says:

          There’s also a poster here who claims that PSS told him ECC is unsupported. Would be great to get some clarity…

  28. Ajikps says:

    Great! Can we expect an updated Sizing Calculator before RTM?

    1. We won’t have that before RTM, no.

  29. supcxc says:

    I found two bugs in the preview version:

    1. The New-MailboxExportRequest cmdlet is missing

    2. The “Get-ManagementRoleAssignment -Delegating $false” cmdlet return nothing

    These cmdlets are used by our current solution. Could you please help? Thanks


  30. David Bird says:

    Where can we find the activation keys for the preview? I am currently testing, and would like to activate it as enterprise to verify against my 2016 server currently in production.

    1. David,

      There are no available activation keys for the preview. This is intentional to ensure that customers do not attempt to place the preview build into production.

  31. Julio Perez says:

    Even though it’s clearly labeled as “Exchange Server 2019 – Preview,” it’s somewhat of a disappointment that Microsoft only puts as system requirements the following:

    Supported Operating System
    Windows Server 2016

    Exchange Setup will enforce system requirements.

    It would have been nice if MORE SPECIFIC information were provided; e.g., memory, disk space, etc.

    There is also little information about the roles Exchange 2019 has available; e.g., mailbox/client access/edge. Why are they being so secretive at this point is a head-scratcher.

  32. Felix Jacob says:

    Will Exchange 2019 continue to support Public folder mailboxes?

  33. henry lei says:

    Can we migrate from exchange 2010 to exchange 2019? And can these two systems co-exist while we are migrating the users?

    1. Hi Henry, you can, but not directly. You’ll have to first migrate fully to Exchange 2013 or 2016 before removing 2010. You can then migrate to 2019. Same n-2 version support as ever.

  34. Klaus Foraboschi says:

    Wehen Exchange 2019 comes out -> will the hybrid version still work with Exchange 2010?

  35. Wally Hasss says:

    Any word on upgrade from 2010, 2013 or 2016? For example, which version is supported to upgrade from?

    1. Wally Hasss says:

      Nevermind I see you need 2013 or 2016. Thanks for the info!

  36. Nick Daniel says:

    Man, I hate being right when it comes to things like this.

    “We strongly believe Office 365 delivers the best and most cost-effective experience to our customers, but we understand that some customers have reasons to remain on-premises.”

    I said it way back in 2015 and had a conversation with some random Microsoft employee about how Exchange is going to be an on-premise product for a log time to come. I strongly disagreed with this guy and when I can remember some key words from that discussion, I’ll follow up to this post in order to make him eat those words. Microsoft just moved Office to an online-only distribution model so the next step won’t even be noticed by people. Exchange is next. They’ve been forcing us to the “cloud” for years and Exchange is dying a slow death. When they finally stop releasing new on-premise versions I’ll keep using old ones as long as I can because I, and the customers I support, will NEVER move our messaging infrastructure to the cloud.

    It’s not just going to happen, it’s currently happning, right now. Farewell.

  37. Faisal Sharif says:

    Hi, I’ve a question. Why Microsoft isn’t shifting Database to SQL DB? I guest they announced couple of years ago but still relying on native DB.

  38. Ajikps says:

    Any word on PA?

  39. DiegonCloud says:

    I need to know about of hosted mode of exchange configuration for more of 10 differents email domains and the docs for build testing on our servers labs. I will wait for your answer. Thanks and best regards !!!

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