Voicemail not being delivered from Phone System to Exchange 2013

[Ryan Steele]

Hi all,

We've been piloting Phone System with Skype for Business Online. We set everything up for delivery of voicemail to our on-premises Exchange 2013 environment per the instructions at https://support.microsoft.com/en-ca/help/3195158/customer-issues-between-exum-and-azure-voicemail. This was working well up until around the middle of October, when we discovered voicemail was no longer being delivered.

Today we finally identified that the system is attempting to deliver these messages through the SMTP fallback mechanism but are being blocked for spoofing because the From: address is using our domain. I've had our mail administrator whitelist the email address the system is using and these messages are being delivered now. However, due to the fact they are being delivered via SMTP they only show up in the Inbox, not in the SfB app or the Voicemail search folder in Outlook.

Is direct depositing of voicemail messages in Exchange on-premises still working for anyone else?

[#2]

After having this discussion in the Teams forum, I have a theory that the issue I'm seeing is specific to the Canadian geo. Is there anyone else out there with their SfB tenant in Canada and is using Phone System who saw a change to the delivery of voicemail around mid-October? This may have affected you even if your email is in Exchange Online. For example, incoming voicemail messages may be now be acted upon by mailbox rules, whereas previously they were unaffected. Voicemail playback controls in Outlook may not be appearing for voicemails received after that date.

[#3]

An update! A new requirement to run the Exchange Hybrid Configuration Wizard has been added to the list of configuration steps for using Phone System voicemail with an on-premises environments. We can't actually test this out until the new year but according to the Office 365 support engineer we've been working with, this should resolve the issues we've been seeing.

It sure would have been nice if Microsoft had given some advance notice of this breaking change and had updated their documentation before it took effect, rather than eight weeks later, but I guess you can't have everything.

[#4]

We have been experiencing this same exact issue but with a completely cloud hosted PBX through Microsoft Teams. Suddenly, a particular users VM's are able to be left, but do not show up in the S4B, Teams or Desktop Polycom Phone at all. I haven't seen the transport rule(s) you mention so maybe this is an expansion of the issue in the cloud. 

[#5]

Do the voicemail messages show up in their Outlook inbox, or do they just not show up at all? If they're not showing up at all, try running a message trace from the Security and Compliance dashboard to see if delivery is failing there.

If they are showing up in the mailbox but not in the SfB app, download the MFCMapi utility and run it on the affected user's computer. Go to Quick Start > Open folder > Inbox, click on one of the voicemail messages in the list, then check the PR_MESSAGE_CLASS property in the lower pane. It should be "IPM.Note.Microsoft.Voicemail.UM.CA".

If the message class is "IPM.Note", it won't show up as a voicemail in SfB. You'll have to work out what is causing this to get changed. Perhaps a third-party mail filter? It's a bit mysterious to me how the PR_MESSAGE_CLASS property is actually meant to be set now that messages are delivered over SMTP rather than through EWS.