Before any firmware upgrade or downgrade, save a copy of your FortiMail configuration by going to Dashboard > Status and click Backup in the System Information widget.
After any firmware upgrade or downgrade, if you are using the web UI, clear the browser cache prior to login on the FortiMail unit to ensure proper display of the web UI screens. Also go to verify that the build number and version number match the image loaded.
The antivirus signatures included with an image upgrade may be older than those currently available from the Fortinet FortiGuard Distribution Network (FDN). Fortinet recommends performing an immediate AV signature update as soon as possible.
Firmware downgrading is not recommended and not supported in general. Before downgrading, consult Fortinet Technical Support first.
Any 4.x release older than 4.3.6 > 4.3.6 (build 540) > 5.2.3 (build 436) > 5.2.8 (build 467) > 5.3.10 (build 643) > 5.4.4 (build 714) (required for VMware install only) > 5.4.6 (build 725) > 6.0.5 (build 148) > 6.2.4 (build 272)> 6.4.5 (build 453)
When upgrading from 6.2.7 to 6.4 release, you must upgrade to 6.4.5 and newer releases, not other older 6.4 releases.
Firmware downgrading is not recommended and not supported in general. If you need to perform a firmware downgrade, follow the procedure below.
- Back up the 6.4.5 configuration.
- Install the older image.
- In the CLI, enter
execute factoryresetto reset the FortiMail unit to factory defaults.
- Configure the device IP address and other network settings.
- Reload the backup configuration if needed.