Not all messages need to be treated equally. When
sendmail processes the messages in its queue, it
sorts them by priority. The priority that is given to a message is calculated
once, when it is first created, and adjusted (incremented or
decremented) each time it is processed in the queue. You can think of
priority as a cost, where mail with the lowest
priority number (lowest cost) is handled first. The formula for the
initial calculation is:
priority = nbytes - (class * z) + (recipients * y)
The items in this calculation are as follows:
Priority of the message when it was first created.
Number of bytes in the total message, including the header and body
of the message.
Value given to a message by the Precedence: line
in the header of the message. The string following the
Precedence: is usually either
junk, bulk, or
list. That string is converted to a numeric value
determined by the P command (Section 25.10) in the sendmail.cf file.
Value given the ClassFactor option (ClassFactor) and a weighting factor to adjust the relative
importance of the class.
Number of recipients to whom the message is addressed. This number is
counted after all alias expansion.
Value given this RecipientFactor option and
weighting factor to adjust the relative importance of the number of
The forms of the RecipientFactor option are as
O RecipientFactor=factor configuration file (V8.7 and later)
-ORecipientFactor=factor command line (V8.7 and later)
define(`confWORK_RECIPIENT_FACTOR',factor) mc configuration (V8.7 and later)
Oyfactor configuration file (deprecated)
-oyfactor command line (deprecated)
The argument factor is of type
numeric. If that argument is missing, the
default value is zero. If the entire
RecipientFactor option is missing, the default
value is 30000 (thirty thousand). The default for the
mc technique is to omit this option.
The RecipientFactor option is not safe. If
specified from the command line, it can cause
sendmail to relinquish its special privileges.