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Office 365 – Understanding Archiving in Lync Online

Understanding the archiving feature in Lync Online can be a bit confusing. Unlike an on-premises installation of Lync Server 2013, there is no option for storing archived data in SQL and thus the only option is integration with Microsoft Exchange.
Office 365 - Understanding Archiving in Lync OnlineWhile having only one option might sound like this should be easier to understand, a Lync Online user’s mailbox can fall into a number of categories depending on whether the mailbox is located on-premises or in Exchange Online. If the mailbox is located in the cloud, the mailbox licensing and archiving settings become relevant to its ability to retain Lync Online archive data.
Complicating the situation is that several articles and even Lync Online policies refer to “Conversation History” as “Archiving” when in fact they are completely separate concepts. With this article, I hope to clear up some of this confusion.

Conversation History vs Archiving

To start, I think it’s important to clarify the difference between the “Conversation History” and “Archiving” features.
Conversation History is dependent upon the Lync client’s integration with Microsoft Outlook and Exchange Web Services (EWS). This integration allows messages to be placed in the “Conversation History” folder in the user’s mailbox if selected to do so in the Lync client and if allowed by policy. The content that is retained is fairly limited and is basically the content of your IMs; there is no meeting content such as whiteboard data or file uploads saved here. Since this is a client side integration, if the connection breaks for some reason, the data might not be saved in the Conversation History folder.
Archiving uses the In-Place Hold functionality of the user’s mailbox to store retained data in the hidden “Recoverable Items” folder of the mailbox; this folder is not visible to the user and is accessed via the eDiscovery tools in Exchange. Archiving in Lync Online is considered “user-level archiving” meaning it is enabled/disabled at the user level, there is no option to enable it globally in the Lync Admin Center within Office 365. The content retained by Archiving includes whiteboard data and file uploads however it will not retain peer-to-peer file transfers, conferencing annotations, audio or video.

How to Enable Archiving in Lync Online

Now that we’ve established that Archiving uses the mailbox’s In-Place Hold feature, enabling Lync Online Archiving really becomes an Exchange task. If your organization separates Lync and Exchange management, it’s time to phone (or IM) your Exchange friend.
In Exchange Online, mailboxes can be placed on In-Place Hold using the Exchange Admin Center or via remote PowerShell. Before doing so, you’ll need to add yourself to the “Discovery Management” role in Exchange Online.
These links cover the process of placing a mailbox on In-Place Hold and selecting the “Lync Items” content:
Create or remove an In-Place Hold
Archive Lync conversations and meeting content to Exchange
A few things to know about In-Place Hold:

  • The Exchange Admin Center is limited to 500 mailboxes per hold whereas PowerShell allows up to 10,000 mailboxes. If you need to place more mailboxes on hold, multiple holds will need to be created.
  • In-Place Hold requires that the user is licensed with an E3, E4 or other license combination that allows for mailbox archiving (E1 does not allow for archiving on its own).
  • The “Recoverable Items” folder of a mailbox technically has a quota of 30 GB; this is separate from the normal 50 GB mailbox quota. This value can be increased by opening a support ticket. According to the Office 365 Roadmap, the quota is scheduled to be increased to 100 GB.

Accessing Archived Data

Now that we’re archiving Lync content, how can we access it? There are essentially two ways to access the data, both performed via the Exchange Admin Center: the eDiscovery search results of the In-Place Hold can be copied to a discovery mailbox or they can be exported to a PST.

Other Items of Importance

Below are a few other items of note related to Lync Online Archiving:
In-Place Hold Criteria
For some organizations, the desire is that Lync conversation data is not archived. While these organizations may have retention policies around email messages, it’s not uncommon for Lync conversation data to be treated differently. For these organizations, it is important that they do not select “Include All Content” when placing a mailbox on In-Place Hold; they will need to “Filter Based on Criteria” and select all message types except “Lync Items”.
Litigation Hold vs In-Place Hold
In-Place Hold was introduced with Exchange 2013 and “Wave 15” of Office 365; prior to that we had the feature “Litigation Hold”. Litigation Hold still exists today and is used by some organizations, especially those that have a requirement to place all mailboxes on hold. One of the main differences between Litigation Hold and In-Place Hold is that Litigation Hold places all mailbox data on hold. Despite this, this article states that a mailbox on Litigation Hold will not retain Lync archive data: Litigation Hold and In-Place Hold in Exchange 2013 and Exchange Online. My testing, however, has shown that this is not the case and that Litigation Hold does in fact retain Lync archive data. For organizations that are not expecting or do not want to retain Lync archive data, this could be an issue.
Archiving != Archiving
While Lync Online does not allow you to create client policies, there are a number of pre-defined policies that can be assigned to users. The names assigned to these policies are a bit misleading as they use the word “archiving” when they really mean “conversation history”. Even the property set by the client policy is ambiguous as setting the property “EnableIMAutoArchiving” to “False” disables “Conversation History”, not “Archiving”.
Meeting Content Retention
Completely independent of the Lync archiving is the retention period for Lync Online uploaded meeting content. Meeting content is retained for 15 days after the last person leaves the meeting with the exception of “Meet Now” meetings that retain data for 8 hours after the meeting end time.
On-Premises Mailboxes
If your mailbox is not located in Exchange Online, archive data cannot be retained for a Lync Online user. Conversation History will still continue to work.
Mobile Clients
The Microsoft documentation on the Lync Mobile Clients indicates that they do not support archiving. My experience, at least with the iOS client, is that IMs from mobile clients are in fact archived in Lync Online. Of course the article refers to “client-side archiving” so it’s not clear if we’re talking about “conversation history” or “archiving”.
Mac Clients
What about the Mac client? I’ve documented that behavior in the article: Office 365 – Understanding Archiving in Lync Online [Mac Edition].


  • Conversation History and Archiving are different in the content they retain and the accessibility by the end-user.
  • The task of archiving Lync Online data is really an Exchange task and is controlled through the In-Place Hold feature.
  • In-Place Holds or Litigation Holds placed on a mailbox could inadvertently archive Lync Online data if the hold criteria is not configured appropriately.
  • On-Premises mailboxes cannot be configured to store Lync Online archive data.
  • Lync Mobile Clients may archive IMs despite the documentation.

Did you find this article helpful?
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Thoughts on “Office 365 – Understanding Archiving in Lync Online”

  1. Very helpful article. One of the things that we are struggling with is different behavior of saving conversation history and archiving depending on whether the users is on a PC vs MAC. Have you done any analysis using a MAC?

  2. Unfortunately I don’t have immediate access to a Mac but I’ll try to hunt one down and see if there are any surprises. I would expect no changes in relation to archiving since that is done on the backend between Lync Online and Exchange Online; the messages that are archived are actually independent of the conversation history messages.
    Thanks for the feedback Ken.

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