MWI Troubleshooting in Exchange 2010 Unified Messaging

Not open for further replies.



We are in the process of testing the Unified Messaging capability of Exchange 2010 and hope to implement it soon. We have found that for certain users the MWI works and some users it does not. I am able to turn up diagnostic logging on the Exchange server and can see the MWI being set when it works and I see no MWI related events at all when calling users where the light does not come on. Because we can see that Exchange is able to send a MWI successfullly to the PBX in some instances, we know that this is not an issue with the PBX. If it were, we would likely see MWI failure messages in the event log. It seems as if Exchange is not attempting to set the MWI at all. Or at least there is no record of it trying for certain users. Do you have suggestions? Or at the very least, can you tell me which other logs, besides the ones marked as UM, would be useful to turn up the logging level?

Thanks. Any help is appreciated.


MWI notification workflow: MBX->UM->IP GW

To trigger the light, SIP NOTIFY message is required to be generated

In order generate a SIP NOTIFY message, the Mailbox Assistant of the MBX server need to query AD to register for appropriate notification at first. After the Mailbox Assistant receives mailbox notification, it maintains in memory state and determines if the MWI state of the users has changed.

If the MWI state of the user has changed, MBX server will proxies the information/request to the UM server within the site. The UM server encapsulates MWI state change information in a SIP NOTIFY message and forwards it to an appropriate gateway

So, please capture the network traces from UM server to IP GW, and check if the SIP NOTIFY is sent properly, you can use WireShark, or Network Monitor

James Luo



Hello, thank you for the reply. I did do a packet capture and did not see any SIP Notify messages in the trace. I also didn't see any SIP Notify messages when the light worked for some users. There is a chance that the SIP Notify messages could be coming from our mail server in another office. However, that wouldn't make any sense since the mailboxes I have been testing on are hosted on the mail server here in this office. Regardless, we have found that when a MWI is attempted to be set, an event shows up in the event log. We are assuming that if SIP Notify messages were being sent, there would be a MWI event in the event log. Since in cases where the MWI does not blink, there are no MWI events in the event log, we are assuming that no SIP Notifies are being sent. We know that our IP-PBX is capable of responding to SIP Notifies.

We've decided to make a call to Microsoft professional support on this. I will update this forum post if we reach a solution with them.


After a few weeks of back and forth with Microsoft PSS on this, we have arrived at a solution. For the user in question, the tech had us do the following:
Make sure there are no more than 10 search folders in Outlook. Numerous search folders apparently can contribute to this issue. (If Applicable) Switch Outlook to Online Mode (as opposed to Cached Mode) Delete the Voicemail search folder in Outlook Log into Outlook Voice Access which will recreate the Voicemail Search Folder

At this point the MWI starting working for us on the extension that previously it was not working for. After this, you can switch back to cached mode if needed. Online mode was only neccessary to delete the voicemail search folder.
Not open for further replies.
Thread starter Similar threads Forum Replies Date
G MWI is Stuck or Delayed with Cisco Unified Communications Manager Exchange Server Administration 5
B Exchange 2010 UM with OCS R2 2007 UM IP Gateway integration- MWI can't be enabled? Exchange Server Administration 7
C Exchange 2010 MWI to UCM Exchange Server Administration 31
J Problem with Exchange UM Message Waiting Indicator MWI Exchange Server Administration 7
Sarge USMC troubleshooting slow startup Using Outlook 6
J Troubleshooting Creating New Outlook Account Using Outlook 1
C Troubleshooting Sync Services for Mac Using Outlook 0
M Outlook 2002 crashes with send/receive...exhausted my troubleshooting knowledge Using Outlook 4
I Exchange 2010 Management Console "Initialization failed" troubleshooting Exchange Server Administration 16
S Exchange 2010 (RTM) Troubleshooting Assistant web access Exchange Server Administration 6
D Troubleshooting rule/script not running Outlook VBA and Custom Forms 5
N Backing Up Exchange Calendar Using Outlook 13
A Ol16 desktopT suddenly can't connect with Exchange Using accounts in Outlook 5
T How can Exchange be configured to sync/push one-way so that the server data can't be affected Exchange Server Administration 0
E How to display "Change Folder" in Change Default Email Delivery Location in Exchange Outlook 2016 Using Outlook 1
J Outlook 2016 Moving IMAP emails to Exchange Using Outlook 1
L How to Import Exchange OST file into Outlook? Using Outlook 3
O Outlook 365 Exchange .ost within Personal Vaul Using Outlook 0
D Outlook 2016 Migrate 'On My Computer' (local storage) Calendar from Mac Outlook to Exchange Account Using Outlook 5
A .restrict results changing after moving to Exchange online Outlook VBA and Custom Forms 0
D Can Exchange Admin Center create a pst for users email/contacts/calendar? Exchange Server Administration 0
S Messages moved / deleted by auto-archive are not synchronized to exchange Exchange Server Administration 8
llama_thumper Setting up forwarders on Exchange server Exchange Server Administration 0
D Importing Outlook Categories from another domain (Exchange 2016/Outlook 2016) Using Outlook 4
M WMI query for Get Disk IO performance in exchange Exchange Server Administration 0
B Outlook 2013/Exchange 2013 - Conf Rooms not fully booking "resolved conflict" meetings Using Outlook 3
D Adding Enterprise Exchange Email Account to Outlook Prevents Sending via Account Using accounts in Outlook 10
O Benefits of Exchange over IMAP and why would I choose Exchange? Using Outlook 2
F Delete/create/reset Exchange mailbox on Using accounts in Outlook 3
A Prevent connection to Public Folders on Exchange? Exchange Server Administration 3
S Add Exchange Account as Secondary to Existing PST? Exchange Server Administration 1
S Adding new Exchange (2016) rule very slow down Microsoft Outlook Exchange Server Administration 0
CWM030 A quick question for Diane about Exchange Exchange Server Administration 2
G How to have domain client use owa server instead of exchange server while connect to network Using Outlook 1
J Outlook 2016 message content does not display -; exchange Using accounts in Outlook 9
C Filter/Search emails sent to internal Exchange address only Using Outlook 2
B Copy/Move Exchange inbox to Pop inbox Using Outlook 4
Fozzie Bear Correct Method to set up accounts as Exchange Using accounts in Outlook 7
P AutoArchive exchange folder to exchange folder Using Outlook 1
J Syncing notes between Outlook 2016/Exchange and Outlook for Android Using Outlook 2
Brian Murphy Exchange Online Everything a Transport Rule should do and cannot Exchange Server Administration 1
E Customer wants a portion of GAL from exchange to sync down to Android contacts via Activesync Using Outlook 2
R Problem with searching public folders Exchange 2013/16 Exchange Server Administration 2
I outlook 2016 manual exchange config Using Outlook 0
R Add Exchange Account to existing POP3 Outlook 2007 Profile Using Outlook 0
Fozzie Bear Office 365 Home Premium with Exchange Online email accounts Using Outlook 3
Commodore Microsoft Exchange Add-in Using Outlook 2
D Winmail.dat with MS Exchange Personal and Using accounts in Outlook 5
I Outlook 2013 Transition to Exchange - weirdnesses Using accounts in Outlook 4
Similar threads