Mail and Messaging Guide
Chapter 5, sendmail administration

Changing the queue processing interval

Changing the queue processing interval

The sendmail daemon started by the /etc/rc2.d/P86sendmail script sets to one hour the interval at which this daemon will fork a process to process the mail queue. You can change this interval by changing the value assigned to the -q argument to the sendmail command in the /etc/rc2.d/P86sendmail script. This interval is typically set to between fifteen minutes and one hour.