Contact Veritas Support directly, as older x64 add-ins are not publicly archived.

Veritas does not host public, anonymous download links for this add-in due to licensing and security protocols. The software must be downloaded via the Veritas Entitlement Management System (VEMS) or extracted from the Enterprise Vault installation media. Unauthorized third-party links often contain malware.

The 64-bit version is a over its 32-bit predecessor.

msiexec /i "EVOutlookAddinX64.msi" /quiet /qn ALLUSERS=1