Backup
DeepFilter lets you take and restore backups from the management panel. The scope of the backup is narrow: what is backed up is the configuration, not the email data. This page explains what is backed up, what is not, and what that distinction means for your disaster scenario.
Scope: what is backed up and what is not
The table below draws a clear line around the contents of the backup file.
| Content | Included in the backup? |
|---|---|
| System settings and scanning preferences | Yes |
| Domain definitions and email routing configuration | Yes |
| Administrator and user accounts, permissions | Yes |
| Domain assignments of domain administrators and read-only users | Yes |
| Whitelist (together with domain scopes) and blacklist entries | Yes |
| Domains excluded from LDAP recipient verification | Yes |
| DKIM private keys | Yes |
| Users' authorized server assignments and domain-specific LDAP profile assignments | No (deleted on restore) |
| End users' personal allow and block lists | No (unchanged by a restore) |
| Quarantined email | No |
| Email traffic analytics (reports, historical statistics) | No |
| Log files | No |
| Email queues (messages awaiting delivery at that moment) | No |
In other words, restoring from a backup brings the server back up with the same settings; it does not bring back past email traffic, the quarantine archive or the historical data in the reports.
Quarantined email is not only excluded from the backup, it is also not kept indefinitely on the server: by default it is deleted automatically after 30 days. This period can be changed from the panel (the lowest value is 1 day, there is no upper limit). If you need to keep a quarantined email for the long term, release it or export it before the deletion period expires.
Email data is a rapidly growing, constantly changing data set; a settings backup, on the other hand, stays small, fast and safe to move around.
DKIM keys and encrypted backups
The backup file contains the DKIM private keys belonging to your domains. These keys are used to sign your outbound email, and if they fall into a third party's hands, signed email can be produced in your name.
Because DKIM private keys are included in the backup, creating the backup file encrypted is recommended. Do not store the password that decrypts the encrypted backup in the same place as the backup file. If you lose the password the backup cannot be restored; there is no password recovery on the product side.
Do not keep backup files in shared folders that people without access to the server can also reach.
Automatic backup
Automatic daily backups can be enabled from the panel. The default retention policy is 7 copies; as each new backup is taken, the oldest copy is deleted. This provides roughly a one-week window to roll back to.
You can change the number of copies kept from the panel to suit your needs. Because backups are small, the disk cost of increasing that number is low.
Moving the backup off the server
By default, backups accumulate on the server's own disk, and the product does not send backups directly to a cloud or remote server address (such as S3 or SFTP). If there is no copy of the backup outside the server, losing the server entirely (a disk failure, the virtual machine being deleted, an incident in the server room) means losing your configuration as well. For that reason, do not neglect moving the backup off the server.
There are several ways to keep a copy of the backup outside the server:
- Sending by email: when you enable this option in the panel, every automatic backup is also sent as an email attachment to the recipient you specify; that way a copy of the latest configuration sits in your mailbox. For details, see the Administration → Backup page.
- Downloading from the panel: you can download the backup file to your computer through the panel and place it in your corporate file storage.
- Writing to external or network storage: you can point the directory the backups are written to at an external disk or network share mounted on the server, so that backups accumulate directly on that storage.
- Infrastructure level backup: if you run the server as a virtual machine, you can use your infrastructure's snapshot or machine backup mechanism.
Whichever route you choose, make sure the backup sits somewhere physically or logically separate from the server. Setting an encryption password is recommended for backups that leave the server; the backup contains the DKIM private keys belonging to your domains.
Restoring
Restoring is also done from the panel. The settings in the uploaded backup file replace the current configuration. The server's current license is kept: the license in the backup is applied only if the target server has no license at all. The operation is written to the audit logs.
Restoring overwrites the current settings. Always take an up-to-date backup before the operation; that way you can go back if you upload the wrong file.
What to check after restoring:
- That the domain list and the destination mail server addresses came back correctly.
- That the hostname and the email identity are as expected.
- That a test message is delivered end to end.
- That the relay IPs defined for outbound email are in place.
- The warnings in the restore summary. Users' authorized server assignments and domain-specific LDAP profile assignments are not backed up and are therefore deleted on restore; redo the assignments whose number the warning reports. Load the keys again for domains whose DKIM key the warning says could not be written. For details, see Management → Backup.
What to consider for your disaster scenario
Because the scope of the backup is narrow, you need to build your recovery plan accordingly. It is recommended that you answer the following questions in advance.
What happens if the server is lost entirely? You install a new Rocky Linux 9 Minimal server, reinstall DeepFilter and restore the settings backup. This gives you a working system; however, the old email in quarantine and the historical traffic reports do not come back.
Is email lost during the outage? Usually not. Sending servers retry messages they could not deliver for a certain period. Even so, it is important not to let recovery take too long; every sending server has a different retry window.
Is the quarantine critical? If you need to retain quarantined email for legal or operational reasons, write both of these points into your plan: this email is not protected by the settings backup, and it is deleted automatically at the end of the default 30 days even when the server is running normally. If you have a long-term retention requirement, increase the retention period from the panel or move the relevant email out of quarantine regularly.
Does your backup actually work? A backup that has never been tested does not count as a backup. At least once a year, perform a restore test on a separate test server and confirm that you still have the password for your encrypted backup.
License status: if you are going to install on a new server, your license needs to be activated on that server. Clarify this in advance, not at the moment of recovery.