While Virtru requires an active internet connection in order to activate, encrypt content, and decrypt content, you can still take advantage of Virtru DLP rules while using Gmail in Offline Mode.
This article will cover how Virtru and Gmail perform in various Offline Mode scenarios.
If you open a new Compose window and your plugin is not activated, you will see that the standard Activate Virtru button is greyed out and that an active network connection is required.
If you attempt to decrypt a message while using an inactive plugin, you will see that the Activate button is greyed out and you cannot decrypt the message.
If Virtru has already been activated on a device, you will not be able to manually toggle encryption on while composing a message. Both your draft and any queued message will be unencrypted. A prompt should indicate that the action is not available while offline.
The info pane will explain that the bar is disabled without an active network connection.
Virtru will, however, still run Data Loss Prevention (DLP) rules on attempts to queue unsecure emails using rules cached from the last time you were online. If you attempt to send a message that would normally trigger an auto-encryption, you will receive a prompt indicating that the message cannot be queued (as an unencrypted message would).
Similarly, if a "Warn" rule is triggered, you will have the option to Cancel (and encrypt later) or Queue Anyway.
If Virtru has already been activated on a device, any attempt to decrypt a message will result in a Network Connection Error.
Just as you cannot toggle Virtru ON to create an encrypted draft, you will also be unable to access any encrypted drafts you may have saved prior to going offline.
If you already had an open encrypted draft when going offline, you will not be able to Secure Send.