Set up comprehensive mail storage

As an administrator, you can ensure that a copy of all sent or received messages in your domain—including messages sent or received by non-Gmail mailboxes—is stored in the associated users' Gmail mailboxes.

Comprehensive mail storage and Vault

If your organization uses Vault, you may want to set up comprehensive mail storage to ensure Vault has full access to your organization's email messages:

Users can send email messages with other core services for Google Workspace besides Gmail. For example:

Calendar—outgoing invitations and messages sent with the Email guests option in desktop Calendar.
Drive—message content sent when users share, transfer ownership, or comment on files in Drive.
Google Docs, Sheets, Slides, and Drawings—messages sent by the app when users email files as attachments or change approvals on files.
Forms—email messages containing forms or links to forms.
Keep—email messages sent when users share notes in Keep.

Comprehensive mail storage ensures messages sent by other core services appear in users' sent folders and are therefore accessible to Vault.

Note: Comprehensive mail storage applies only to core Google Workspace services. Additional Google services may be able to send email messages on behalf of users. Messages sent by those services might not be stored in users' sent folder and might be unavailable to Vault.

For organizations that reroute messages to non-Gmail email servers, you can set up comprehensive mail storage to ensure that all messages are stored in Gmail mailboxes and are available to Vault.
You can also set this up if you have a non-Gmail system that uses the SMTP relay service to route messages on behalf of your users—for example, for ticket tracking systems, bug databases, or automated notification systems—and you want to display the messages in your users' Gmail mailboxes. This is critical for storing messages in Google Vault for all users who enable SMTP relay.

Considerations before you enable comprehensive mail storage

There are some important considerations to carefully review before enabling comprehensive mail storage:

You should not enable comprehensive mail storage if you have compliance routing rules that change the recipient (and don’t want the original recipient to receive a copy of the email).
When you have the SMTP Relay service enabled, user mailboxes will keep a copy of the message in the sent folder (for example, when sending mail from a scanner) if comprehensive mail storage is enabled. This might cause accounts to exceed storage limits if your account's edition has storage limits. Compare editions.
You should enable comprehensive mail storage if you only use Gmail for the Vault feature and forward email to your on-premise mail server or other email provider.