The qmail-send
and qmail-smtpd
logs easily demonstrate how busy the system is. Both logs provide a status indication of how many messages are handled concurrently at any given time and the limit on this concurrency. These status log entries combined with their timestamp give a picture of the load over time. Tracing a message through the system is relatively easy to do by hand: first, find the point where the message is injected into the queue, use its inode number to find the message's delivery attempts then use the delivery numbers of these attempts to locate the results of these attempts. When using a script to determine the same information, the potential reuse of the various identification numbers makes correct analysis rather tricky.
To assist with analyzing the qmail-send
logs, Dr. Bernstein wrote the qmailanalog software package (http://cr.yp.to/qmailanalog.html). This package excels in generating summaries of the qmail-send
logs and has some limited ability...