Please find the following KB articles to assist you in external monitoring:
Does AsyncOS support SNMP monitoring?
ESA, SMA, and WSA Queries with the snmpwalk Command Configuration Example
How do you test the SNMP trap capability without simulating actual outages or service-impacting events?
For full information regarding XML/SNMP monitoring:
XML, as you have requested more on, is used to monitor the statistics of email processed through the appliance.
For full documentation regarding XML – please see the Daily Management Guide (page 315).
SNMP can be used to monitory overall system health, including the hardware.
For full documentation regarding SNMP monitoring – please see the Daily Management Guide (page 306).
The Daily Management guide can be located at the following link, as is recommended to be downloaded from there due to the size:
http://www.cisco.com/en/US/products/ps10154/products_user_guide_list.html
