UTORmail Message Size Distribution

UTORmail message size plot This is a plot of the cumulative distribution of the size of e-mail messages handled by the UTORmail system. The x axis is the size of the message in bytes on a logarithmic scale. The y axis is the number of messages of that size or greater. The dates are the middle Wednesday of March, July, and November.

The difference between the left side of the curves is just a reflection of the different numbers of messages handled on each date; see next plot.

UTORmail total number of messages Here is the total number of messages delivered on each day. The November and March values are increasing linearly.

percentiles of message size Here are the 10,20,...,90 percentiles (deciles) of the message size plotted on a logarthmic scale vs time. For example, the bottom line represents the 10th percentile - 10 percent of the messages are this size or smaller. The middle line, the 50th percentile, is also the median: half the messages are this size or smaller.


  • the lower lines are all rising almost linearly, which means a constant factor increase (e.g. doubling in size) over time
  • the 70, 80, and 90 percentiles are increasing at an even a faster rate

Created and maintained by Peter Ip, Network Services Group. E-mail: peter.ip@utoronto.ca

Copyright © 1996-1999 University of Toronto