Attention
Usually, upgrading iRedMail is just updating some config files to achieve new features or fix bugs, you do NOT need to download the latest iRedMail and run the script.
Do NOT skip releases. Upgrades are only supported from one release to the release immediately following it.
If you're looking for upgrading a very old iRedMail server to the latest iRedMail release, there's an alternative solution: Migrating to a new iRedMail server.
Paid Remote Upgrade Support
We offer professional remote upgrade support if you don't want to get your hands dirty, please check the details and contact us.