The MsgFiler Engine is an Apple Mail Plug-In that is a **required** add-on for MsgFiler 3 running on macOS from Mountain Lion to Ventura. It speeds up mailbox loading and filing performance to remote IMAP mailboxes.
{% hint style="danger" %}
The MsgFiler Engine Plug-In no longer works on macOS Sonoma and higher. Please upgrade to MsgFiler 4 from the Mac App Store and be sure to install the MsgFiler Engine Filing script during the MsgFiler 4 installation process.
{% endhint %}
* [Download MsgFiler Engine](/support/engine/download.md)
* [Installing the Plug-In](/support/engine/install.md)
* [Accessibility and Automation](/support/engine/accessibility-and-automation.md)
* [Removing the Plug-In](/support/engine/uninstall.md)
* [Troubleshooting](/support/engine/troubleshooting-engine.md)
* [Version History](/support/engine/version-history.md)
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