When you configure an Enterprise Vault server to support Outlook RPC over HTTP client access, you create the ExchangeServers.txt file, before you run the owauser.wsf script to configure the Data Access account.

ExchangeServers.txt holds the IP addresses of all the Exchange RPC target Servers that will contact the Enterprise Vault server. When configuring this file for clustered Exchange Virtual Server configurations, the file must include all the IP addresses of the Exchange Virtual Servers that will access the Enterprise Vault server, and all the IP addresses of the physical computers (nodes) on which the Exchange Virtual Servers can run.