Name
MaxDaemonChildren
Synopsis
The sendmail program fork(3)s often. It forks to process each incoming connection, and it forks to process its queue.
You can limit the number of forked children that the listening
sendmail daemon produces by defining the
MaxDaemonChildren
option, the forms of which are
as follows:
O MaxDaemonChildren=num ← configuration file (V8.8 and later) -OMaxDaemonChildren=num ← command line (V8.8 and later) define(`confMAX_DAEMON_CHILDREN',`num')← mc configuration (V8.8 and later)
The num
is of type
numeric and specifies the maximum number of
forked children that are allowed to exist at any one time. If
num
is less than or equal to zero, if it
is missing, or if this entire option is missing, no limit is imposed.
If num
is greater than zero, connections
that cause more than that number of forked children to be created
will be rejected. While rejecting more connections,
sendmail will change its process title to read:
rejecting connections: maximum children: num
If num
is greater than zero,
sendmail will also limit the number of forked
daemon children it creates to handle queue runs.
If the daemon handling incoming mail has this option set, a
denial-of-service attack can easily be launched against your machine.
Beginning with V8.8, the ConnectionRateThrottle
option (ConnectionRateThrottle) can be used to slow rapid
incoming connections and can be used with the incoming daemon.
The MaxDaemonChildren
option is appropriate for use in certain queue-processing situations. ...
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