The command msiexec qr i sophosoutlookaddinsetupmsi t1 ec3 c1 i1 work is a specific instruction to silently deploy the Sophos email security plugin with a reduced user interface. However, the syntax regarding the latter half of the string appears garbled or is a copy-paste artifact from a log file.
Examples:
: Determines if the encryption options are user-configurable (Value often locks specific settings as per admin policy). msiexec qr i sophosoutlookaddinsetupmsi t1 ec3 c1 i1 work