3 Ways to Keep Voicemail & Auto Attendant when Upgrading to Skype for Business 2019

Those of us who use voicemail in Skype for Business face a quandary.

We did get a new Skype for Business Server, as well as a new Exchange Server. But we’re missing one component: the Unified Messaging service in Exchange Server 2013/2016. Exchange Server 2019 will NOT have Unified Messaging.

The sysadmins reading this already know what that means. They can feel it as a sudden clench in the chest. Skype for Business’ voicemail needs Unified Messaging. Without it you’ll end up upgrading a part of the office’s phone system away!

Two, actually…the Auto Attendant’s gone too. No more, “Press 1 for Customer Service. Press 2 for Sales…”

What do we do? If your offices use Skype for Business on-prem and employ Unified Messaging for voicemail and/or Auto Attendant, it’s time for some alternative thinking.

Fortunately, we’re all IT pros. We’re good at creative solutions. That’s what we’ll have to do here, to preserve Unified Messaging.

The Path to IT Solutions
The IT professional’s configuration thought process. (Sure feels like it sometimes, doesn’t it?)
Photo by Jaromír Kavan on Unsplash.

Right now we have 3 ‘preservation’ options, each with different levels of expense & usable time. Time to run some comparisons!

Voicemail/AA Preservation 1: Keep Your Exchange 2013/2016 Server On-Prem

This is a way to preserve UM within the Microsoft infrastructure. It involves juggling between different versions of Skype4B and Exchange. Essentially, you upgrade your Skype for Business Server to 2019…but not your Exchange Server. It stays at its current version. Accounts and configuration intact.

You’ll need to undertake several processes. Changing the UM dial plan, voice policies, etc. It all depends on your existing Exchange Server’s configuration. Here are resources to help you:

VERDICT: The most direct solution. With a critical flaw – it has a lifespan. Exchange 2016 will run out of mainstream support in October 2020. Extended Support runs until October 2025, which lets you stretch things more. You’re still faced with the potential of higher support costs the longer you go.

This is the option I prefer, frankly. Even with the lifespan boundary. You retain the most control, and it requires almost no new hardware.

If you don’t run Exchange 2016 already, or the lifespan boundary doesn’t work, then we have Option 2.

Voicemail/AA Preservation 2: Switch to Cloud Voicemail/Cloud Auto Attendant (Hybrid Deployment)

Cloud Voicemail is Microsoft’s response to yanking Unified Messaging out of Exchange. It’s (predictably) a part of Office 365, and requires a tenant to operate. Same with Auto Attendant—now it’s a cloud service too.

Cloud Server Ports

Setting up Cloud Voicemail isn’t that complicated. You must have hybrid connectivity enabled first, of course. I’d even recommend doing this a week in advance, so you can test & verify successful connectivity.

To configure Cloud Voicemail, you’ll need:

  • Your Office 365 tenant account login/password
  • The domain assigned to your tenant
  • Administrative access to your Skype for Business Front End and Edge Servers
  • Administrative permissions on PowerShell
  • At least one test user account

Once you have those together, follow the steps here. It’s basically a handful of cmdlets: How to Configure Cloud Voicemail – Microsoft Docs

If you already have a hybrid deployment, using Exchange Online, Microsoft will transition you to Cloud Voicemail in February 2020.

Cloud Voicemail is not a 100% drop-in replacement for Unified Messaging though. According to ExPTA.com, Cloud Voicemail doesn’t include Play on Phone, call answering rules, text notification, or Outlook Voice Access. Doesn’t mean those won’t show up down the line, but for now, Cloud Voicemail’s sticking to the basics.

VERDICT: If you want to move to Exchange Server 2019, you’ll have to switch either to Cloud Voicemail or Option 3. Exchange 2019 doesn’t have the Unified Messaging service. This might help to gradually introduce Office 365 tools to the company. You also get Teams this way, which could provide a transition path for all staff…if you’re going that way.

Voicemail/AA Preservation 3: Integrate a Third-Party Voicemail/Auto Attendant Service with Skype for Business

This option essentially abandons using Exchange Online, Cloud Voicemail, and Office 365. Instead, you add in a third-party service to provide your users voicemail and/or an Auto Attendant feature.

We have a curious reversal on this track. It’s relatively easy to add in Auto Attendant…several third-party providers exist to do just that.

However, voicemail’s a little harder to add in. I came across two solutions that appear to work with Skype for Business Server:

As far as I know, we haven’t worked with either of these solutions directly in a Skype for Business topology. If you have, please share your thoughts in the comments.

VERDICT: If you do want to upgrade to Exchange Server 2019, but don’t want anything to do with Office 365, this is your only option to preserve voicemail and/or Auto Attendant.

Preserving Unified Messaging: Unfortunate, but Necessary.

I can understand why Microsoft chose to remove Unified Messaging. It falls within their “cloud first” mission, consolidating things like voicemail & Auto Attendant into the Azure/O365 ecosystem. (Must have taken a LOT of coding…)

That said, those of us who appreciate on-prem control now have another instance of “technical gymnastics.” Trying to find a new solution for a resurgent problem.

Unless of course you want to drop Unified Messaging? I can’t think of a scenario when a business would voluntarily drop its voicemail/Auto Attendant…but that doesn’t mean it doesn’t exist. Perhaps you’re considering the idea?

Auto Attendant Virtual Assistant
Maybe use a Virtual Assistant instead? “Hello, you have reached XYZ Corp. Press 1 for Sales…”
Photo by Fezbot2000 on Unsplash.

In terms of how these processes shake out…we do have a full Skype for Business Server 2019 installation planned this year. We’ll most likely use Preservation 1, maintaining our current Exchange 2016 server. (Exchange 2019 will have a separate test.) I will document EVERYthing as we go, and produce plenty of blog posts from that.

If you’re planning a Skype4B 2019 upgrade, which Unified Messaging preservation method will you use?

How to Preserve Unified Messaging

4 thoughts on “How to Preserve Unified Messaging

  • April 26, 2019 at 2:00 pm

    Hi Chris,

    Thank you very much for your post. Always great to see what’s going on for others 😀

    I deployed Skype for Business Server 2019 and hundreds of users are already using this infrastructure. I have been on a rush because my Boss deployed Exchange 2019 and moved lot of guinea pigs + new employees (from a merge) on it. Need a raise.

    We then are running Skype for Business 2015 with Exchange 2016 + Skype for Business 2019, Exchange 2019 and Cloud Voicemail.

    To keep it short, at the end, we will use the second method you mentioned : Switch to Cloud Voicemail. If I’m not wrong, you don’t need extra licenses if you run the infra on-prems.

    Regarding the Voicemail features, ExPTA.com is not totally up to date. Microsoft added some stuff. We don’t have comprehensive features like we used to have with EUM (Play on Phone, (WMI ?!), Who’s reaching me ? Am I out of office ? What day / time is it ? etc.), but they recently added a section : Choose how you want your calls to be handled when they reach the voicemail service; Including :
    • Don’t play greeting, and hang-up (Not existing with EUM)
    • Play greeting, then hang-up (Not existing with EUM)
    • Play greeting, then transfer the call (More basic than is used to be)
    • Play greeting, then allow the caller to record a message
    • Play greeting, then allow the caller to record a message or transfer to the target user

    You can also easily change the language you want to use for yourself when you reach your own voicemail or for text-to-speech features.
    Finally, you can define the message when you’re absent : Customize an Out of Office greeting message, and choose to play it to callers all the time, based on your Outlook auto-reply status, or calendar OOF status.

    Biggest change, indeed, we now receive a simple email with MP3 attached and basic caller’s information. Translation service may look more reliable than EUM’s one, since Microsoft looks to be able to detect multiple languages. I have troubleshooted our new infrastructure for months now but I’m still not able to receive any new Voicemail messages notifications within any Skype for Business clients. “Show more within Outlook” still point to “Voice Mailbox” filtered folder where new messages are not considered as “Voicemail”. Microsoft (O365) also started to use my UPN as recipient instead of my real one defined within O365 (AD sync) for any new missed calls notifications or voicemails. Maybe an important information, it looks like having UPN at least as alternative alias is more than highly recommanded ! I added my UPN as alias and I have received new notifications (I lost a lot of messages without any notice).

    /!\ If anyone would like to help me or give me information about Skype for Business client notifications, I would highly appreciate ! Feedback from a Microsoft employee : Don’t know. Who uses voicemailbox in 2019 anyway ?

    Regarding the Auto Attendant. I have to say, I have no idea what is the purpose of this feature. We use Skype for Business workflow for all stuff related to “Hello, you have reached XYZ Corp. Press 1 for Sales…”. I’m not really Exchange guy myself so maybe I’m missing important parts there.


    • May 7, 2019 at 10:02 am

      Thanks very much for this response! You win the ‘most detailed comment’ award for 2019, full stop.

      Interesting point about the notifications. Wonder if this is a bug…note made to check.

      • June 6, 2019 at 1:51 am

        Hi Chris,

        With Microsoft TAP program feedback, we have been able to sort the notifications stuff out.

        Skype for Business still use EWS to show missed calls and voice mails notification. Since we have begun to test Cloud Voicemail, we have received email from our O365 tenant, which is quite expected, of course.

        The problem resides in the fact that Exchange Hybrid mode doesn’t support 3rd party email gateway (proofpoint). Indeed, our proofpoint messed up the header and notifications were not considered.

        We were able to see this kind of messed headers :

        Content-Class: unauthenticated,Voice-CA
        instead of :
        Content-Class: Voice-CA


        Content-Class: unauthenticated,MissedCall
        instead of :
        Content-Class: MissedCall

        At first we tried to play with the headers. It worked but we were not able to see the caller’s information : anonymous@anonymous.invalid

        We have then defined new rules to bypass the proofpoint and all is working fine now.


    • November 29, 2019 at 5:11 am

      Just catching this comment:
      “Biggest change, indeed, we now receive a simple email with MP3 attached and basic caller’s information.”

      This was already native to Exchange 2016 UM. Wish MS could have left the product line as it was, but I get it I suppose. I think all this change was about shifting those dev guys over to the cloud division to help polish MS Teams voice, with the by product being the decision tries to “force” the on-prem folks to start to move over. We’re years and years away from ever considering off-prem systems ourselves so, even a toe dip in the water isn’t an option… ah well. We’ll be trying the XMedius solution over the next couple weeks. Will try to remember to update with results!

      cheers and happy holidays to all,


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