authservice is set to 1 and
authservicettl is positive, the MMP will allow queries about who is currently logged into the MMP, for the purpose of POP before SMTP relay authentication. This option is available at the
vdomain levels. This option should almost never be turned on globally; you should configure this by virtual domain. Setting the
authservice parameter to 1 permits probing of the authservice cache with the xqueryauth ip-address command over the POP protocol.
The default value is: 0