Technical Tip: Storing mail data and quarantine reports in config-only HA mode

For FortiMail units operating in server mode as a config-only HA group, mail data must be stored on a NAS server instead of being stored locally. If mail data is stored locally, email users’ messages and other mail data may be distributed across multiple FortiMail units.

Even when FortiMail units are not operating in server mode with config-only HA, storing mail data on a NAS server can provide several benefits. For example, if the NAS server is backed up regularly, the risk of mail data loss can be reduced. In addition, if a FortiMail unit experiences a temporary failure, mail data can still be accessed on the NAS server. Once the FortiMail unit restarts, access to the mail data stored on the NAS server can typically be resumed.

For config-only HA groups using a network-attached storage (NAS) server, quarantine reports are sent to email users only by the primary unit. The primary unit also functions as a proxy between email users and the NAS server when FortiMail webmail is used to access quarantined emails or when users configure their own Bayesian filters.

For an active-passive HA group, all mail data is read from and written to the NAS server by the primary unit, in the same way as a standalone unit. If a failover occurs, the new primary unit continues to use the same NAS server for mail data. All mail data previously stored on the NAS server by the original primary unit can be accessed by the new primary unit. Therefore, when a NAS server is used for mail storage, operation can continue after a failover without any loss of mail data.

Remote storage can be configured from the following path:

Mail Settings → Settings → Storage.

This tab allows the configuration of local or remote storage for mail data, including mail queues, email archives, user mailboxes, quarantined emails, and IBE-encrypted emails. FortiMail units can store email data either locally or on a remote storage server.