Authservice Option
From MsgServerDocWiki
If 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 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

