Exchange Ingestion

Document created by user.oxriBaJeN4 Employee on Sep 15, 2015Last modified by user.bx3iB36ab3 on Sep 4, 2018
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This feature is currently in BETA, please contact for more information.


The Exchange Ingestion feature provides the capability to add legacy messages from Exchange mailboxes directly to the Mimecast archive. Once archived, messages are available for Administrators and end users using the archive search features in Mimecast applications.


Exchange Ingestion requires the installation of the Mimecast Synchronization Engine application in the company network. Once installed Administrators can create batches of mailboxes to be ingested using the Administration Console.




This provides the following benefits:

  • Enhanced value of historical corporate data, by combining legacy mailbox data with current data and making it accessible to Administrators and end users using Mimecast Applications.
  • Enhanced risk mitigation and compliance, once ingested, data is tamper proof and stored in geographically dispersed data centers.
  • Self-service ingestion, where Administrators are in control of which mailboxes are ingested to Mimecast and when.


Supported Environments


The following Exchange environments are supported for Exchange Ingestion:

  • Exchange Server 2007 SP 1 and later.
  • Exchange Server 2010.
  • Exchange Server 2013.
  • Exchange Server 2016.
  • Office 365.


Scenario Overview


There are 2 primary scenarios for Exchange Ingestion, importing legacy mailbox data from Exchange to Mimecast, and backfilling an existing Mimecast archive with data that may have been missed due to configuration or other unplanned issues.


Legacy Mailbox Data Import

New Mimecast archiving customers, or existing customers upgrading to an archiving package, typically want to import legacy data from Exchange mailboxes into the Mimecast archive to take advantage of the benefits this brings.


Understanding Data Flow

The Mimecast Synchronization Engine polls Mimecast at regular intervals for changes to the site configuration, for example, a new Exchange Ingestion batch. When a change is detected it will proceed to connect to Exchange / Office 365 and start extracting data.

As the data is extracted from the mailbox, the Mimecast Synchronization Engine will confirm the availability of each message in the Mimecast archive:

  • Messages not discovered in the archive are ingested.
  • Message discovered in the archive are not ingested to prevent duplication.




The Mimecast storage API’s operate throttling logic to maintain the performance of all relying services. Where throttling is applied to an Exchange Ingestion batch versions 4.0 and later of the Mimecast Synchronization Engine use a backoff mechanism before retrying an item that has been subject to storage throttling. By default, this backoff period is 60 minutes.


Where Mimecast throttling is being applied it is possible the Ingestion batch will report the In Progress status and the Mimecast Synchronization Engine will continue to process the ingestion until all items in the batch have been successfully ingested.



Duplicates within any data being ingested at any time, within the one process or across multiple processes at different times, will be de-duplicated (if containing the same message ID and sent date). However, if an item is already archived via journaling or external email flow through Mimecast, another copy being ingested will duplicate within the archive causing two copies to exist in the archive.




  • All communication is sent securely over an encrypted HTTPS channel.
  • Mimecast supports TLS 1.0, 1.1, and 1.2 protocols for inbound connections to public API's.