UTORmail Mailbox Sizes

number vs mailbox size This plot shows the cumulative distribution of mailbox sizes on the UTORmail system. The x axis is the size of the mailbox in bytes, on a logarithmic scale. The y axis is the number of mailboxes of that size or greater.

The curves rise with time because the total number of mailboxes increase with time. Compare with the UTORmail accounts plot.

The method of calculating the mailbox size changed on 19990514. Before, only the INBOX was counted, and the size was the number of bytes in the INBOX. After, all folders were summed, and the size was the number of blocks (kilobytes) allocated

The default INBOX format changed in Sep 2003 from UNIX format to MBX format, resulting in bigger small INBOXes.

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


  • most of the curves appear to be well fit by straight lines, meaning the percentiles are growing by a constant factor with time (e.g. the time it takes to double in size is constant)
  • the slopes are higher for the higher percentiles, meaning that the bigger mailboxes are growing faster

total diskspace vs time Here is the total diskspace used vs time plotted logarithmically.

The 'fit' is a least-squares fit of a straight line to the 'all' data (log(all) vs time), ignoring the data before Jan 2000. The "doubling time" is estimated from this fit.

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

Copyright © 1996-2004 University of Toronto