The rshost utility is used to deploy changes to the relay server configuration file to a running instance of the relay server running on the same machine. The format of the rshost command line used to update the configuration file is as follows:

rshost -u -f <filename>

The -u option instructs rshost to detect configuration updates and apply them to the currently running relay server. The -f option is used to specify the new configuration file. See rshost utility.

Updated configuration files can be applied to individual relay servers in the farm one at a time. Be careful when editing the configuration file while relay servers are running.