Cisco Cisco Email Security Appliance C690 User Guide
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Cisco AsyncOS 8.5 for Email User Guide
Chapter 31 System Administration
Alerts
Because alert messages can be used to inform you of problems within your appliance, they are not sent
using AsyncOS’s normal mail delivery system. Instead, alert messages pass through a separate and
parallel email system designed to operate even in the face of significant system failure in AsyncOS.
using AsyncOS’s normal mail delivery system. Instead, alert messages pass through a separate and
parallel email system designed to operate even in the face of significant system failure in AsyncOS.
The alert mail system does not share the same configuration as AsyncOS, which means that alert
messages may behave slightly differently from other mail delivery:
messages may behave slightly differently from other mail delivery:
•
Alert messages are delivered using standard DNS MX and A record lookups.
–
They do not use
smtproutes
in AsyncOS versions older then 5.X.
–
They do cache the DNS entries for 30 minutes and the cache is refreshed every 30 minutes, so
in case of DNS failure the alerts still go out.
in case of DNS failure the alerts still go out.
•
Alert messages do not pass through the work queue, so they are not scanned for viruses or spam.
They are also not subjected to message filters or content filters.
They are also not subjected to message filters or content filters.
•
Alert messages do not pass through the delivery queue, so they are not affected by bounce profiles
or destination control limits.
or destination control limits.