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Exchange Online Unified Messaging being replaced with Cloud Voicemail starting March 2019, final retirement February 2020

In July 2018 we learnt that Exchange Server 2019 no longer contained the Unified Messaging (Voicemail and Auto-attendant) role. It figured that it was only a matter of time before Microsoft retired the service in Office 365. That time has now been announced.

Microsoft is retiring Unified Messaging (UM) in Exchange Online and replacing it with Cloud Voicemail and Cloud Auto Attendant services. If you have Skype for Business 2015 or Lync Server 2013 hybrid connected to Exchange Online Unified Messaging you will be transitioned by Microsoft to Cloud Voicemail on or before February 2020.

You are impacted if you are using Exchange Online for

  • Voicemail service
  • Auto Attendant service
  • Fax integration

Lync 2010 Server is not supported to connect to Cloud Voicemail. Lync 2010/Exchange UM Online customers must upgrade to Skype for Business Server 2015 or 2019 prior to February 2020 to be supported on Cloud Voicemail.

Microsoft previously announced retiring the option to connect third-party IP PBX’s/Session border controllers to Exchange Online Unified Messaging on December 1, 2019.

Who is unaffected?

  • Exchange Server customers using Unified Messaging are unaffected.
  • Skype for Business Online and Microsoft Teams users are unaffected, they have always used Cloud Voicemail.

How the transition will work


Reference: Exchange Unified Messaging Online migration support

From the blog “The transition timing will vary depending upon how your company has utilized the UM features. Over the course of this calendar year, we will selectively notify customers via the Office 365 Message Center of their coming transition. The first group of customers will be notified in February 2019 and then can expect to be transitioned in March 2019. The experience for each customer will be transparent – Microsoft will switch your users over to Cloud Voicemail and perform the necessary validation and testing.

Customers who have received a transition notification and would like to request postponement can do so by submitting a request via the support tool in the Office 365 Admin Portal. Please remember that final retirement date is February 2020.”

What’s missing from Cloud Voicemail compared to Exchange Online Unified Messaging

The Microsoft blog does a good job of selling the benefits of Cloud Voicemail, mainly around being in the cloud is great for future innovation. Most typical users will not notice any real difference. However, today, there are a few feature gaps between Exchange Unified Messaging and Cloud Voicemail. To Microsoft’s credit, their documentation spells this out. Here are some notable ones:

  • PSTN Dial-in Access – Cloud Voicemail has no option to dial a regular phone number to listen back to your voicemail. For example from your mobile/cell phone. All listen back is via your email.
  • Play on phone (PSTN)- to play message – the ability to click play and have your PSTN phone ring and play the message back to you. useful for those without headsets/speakers on their PC.
  • Call Answering Rules/Personal Auto Attendant (now available)
  • Message Waiting Indicator light on some phones
  • Sending a voice message to a group of users
  • Voicemail notification using SMS
  • Fax integration – I don’t know of anyone who used this, but it’s gone

Missing today but coming:

  • Web portal administration – CY19

What’s missing from Cloud Auto Attendant compared to Exchange Online Auto Attendant

  • Transfer to PSTN number externally – coming Q2CY19
  • Extension dialling – CY19
  • Mailbox for AA callers to leave a message – CY19

Have I missed a feature you use, if so please let me know. I will keep updating the blog to help others.

Overall I don’t think this will impact a lot of users functionality wise. It is another example of the type of change timelines in the cloud.

About the author

Tom Arbuthnot

A Microsoft MVP and Microsoft Certified Master, Tom Arbuthnot is Founder and Principal at Empowering.Cloud as well as a Solutions Director at Pure IP.

Tom stays up to date with industry developments and shares news and his opinions on his, UC Today Microsoft Teams Podcast and email list. He is a regular speaker at events around the world.

  • Features that are lacking. Direct Routing to auto attendants is not supported – you must port your number to Microsoft as a Service Number. There is no such thing as a subscriber access number – this is commonly used with shared voicemail boxes. There are no shared voicemail boxes. No option to “Zero Out” of a voicemail box which is commonly used in Boss/Admin scenarios. No ability to schedule temp/holiday greetings.

  • How can I tell if my Auto Attendants from ExchUMO have been moved to the Cloud Auto Attendant infrastructure?
    I’m sure there is some kind of Remote PS command to run but I can’t seem to find it.

    • Hi Mark,

      I’m not sure your AutoAttendants will be automatically moved. ExUM AA and Cloud AA have different features, so some mapping decisions will need to be made.

  • Hi Tom,

    If you’re using Cisco CUCM with Exchange 2010 UM on-prem for voicemail and want to migrate users to Exchange Online (using a hybrid Exchange 2016 deployment), user mailboxes migrated to Exchange Online will no longer have voicemail as there is no option in this scenario?

    • That’s right, there will be no first party (from Microsoft) option to connect your SIP IP PBX to Exchange Online for Unified Messaging/voicemail.

      I believe AudioCodes and AnyNode might have third-party gateways, but I haven’t had hands-on with them

  • Hi Tom,

    We have implemented an hybrid environment consisting of Skype for Business Server 2015 On Premise and Exchange UM Online, I have 2 questions:

    1. Will this change be transparent or will it affect in some time our Voicemail service?

    2. We need to migrate to Microsoft Teams? or the new Cloud Voicemail will can work with our Skype for Business Server 2015 On Premise infraestructure?


  • The subscriber access number feature is a big loss for our users while migrating from legacy pbx

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