You do not need to upgrade earlier versions of the Enterprise Vault 8.0 Outlook Add-Ins. The earlier Outlook Add-Ins are compatible with Enterprise Vault 8.0 SP4. The only limitation is that new client functionality is not available until you upgrade.

When you upgrade from Enterprise Vault 8.0 or later, you can upgrade the Enterprise Vault Outlook Add-Ins before or after you upgrade the Enterprise Vault servers.