When the queues are processed normally, sendmail
will attempt to deliver all messages (except those that have a
recipient address that resolves to a delivery agent with the
F=% flag (F=%) set). No
distinction is made between recently queued messages and messages
that have been in the queue for a long time.
Some sites might prefer to process the queue oftensay, once
every five minutes. This ensures that all important mail will be
delivered promptly but can exact a price in degraded performance.
Every time the queue is processed, sendmail
tries to deliver every mail message in the queue, but many sites have
queued messages that should not be retried every five minutes. One
way to handle this problem is to set the
MinQueueAge option. If it is set to
1h (one hour), every queued message is forced to
remain in the queue for a minimum of one hour, even if the queue is
processed more frequently. The forms of this option are as follows:
O MinQueueAge=wait configuration file (V8.7 and later)
-OMinQueueAge=wait command line (V8.7 and later)
define(`confMIN_QUEUE_AGE',`wait') mc configuration (V8.7 and later)
The argument wait is of type
time. If wait is less
than or equal to zero, or if it is missing, this feature is disabled.
If the units in the time expression are omitted, the default is
minutes. There is no default for the mc
Note that the decision to process is not based
on the time the message was placed into the queue. It is instead
based on the time the message was last processed from the queue. This
time is stored in the K line of the
qf file (K line). This
minimum is enforced only if the number of times delivery has been
attempted is greater than zero (the qf
file's N line, N line). This ensures that the first delivery attempt
will be made immediately.
The MinQueueAge option is safe. If specified from
the command line, sendmail will not relinquish
its special privileges.