Misc options

Enable Finger Service
Enables simple network protocol for human-oriented status and user information exchange. Changing this setting requires manual "AfterLogic XMail Server" service restart.
Finger service port
This port is used to establish Finger connections.
Max MTAOps
Maximum number of MTA relay steps before treating message as looped. Prevents endless forwarding messages (default 16).
Smart DNS Host
Smart DNS hosts list (with recursion bit set to true) DNS queries are directed to. Such DNS hosts must support DNS recursion in queries. The format is:
dns.home.bogus.net:tcp,192.168.1.1:udp,...

Disk & Memory Consumption Server Quotas

SMTP Minimal Disk Space
Minimal disk space (in Kb) requested before accepting an SMTP connection.
SMTP Minimal Virtual Mem
Minimal virtual memory (in Kb) requested before accepting an SMTP connection.
POP3 Minimal Virtual Mem
Minimal virtual memory (in Kb) requested before accepting a POP3 connection.

Mail Headers Processing Options

Disable Emit Auth User
If emitting auth users is enabled, XMail adds special headers (XAUTH-***) to each message authenticated user works with. This allows logging user's action within message headers block.
Received Header Type
Verbosity of "Received" header. Any SMTP server adds such header to each inbound and outbound message. This allows tracking message delivery path.