tls              (on|off)    set to 'on' to enable TLS
tls_skip_verify  (on|off)    trust server TLS without verification, defaults to "on" (verify)
client_tls_cert  (path)      path to client certificate for mTLS auth
client_tls_key   (path)      path to client key for mTLS auth
queue_dir        (path)      staging dir for undelivered messages e.g. '/home/events'
queue_limit      (number)    maximum limit for undelivered messages, defaults to '100000'