Parsing of the mailstats program's output can be made more program-friendly with the use of the -p command-line switch described earlier. One drawback of using the -p command-line switch is that it both prints and zeros the statistics.

Beginning with V8.12 sendmail, it is possible to print in program-friendly form (as with -p), but not zero the statistics. This is done with the -P command-line switch. This switch is identical in all respects to the -p, but it does not zero the statistics.