John Borwick’s blog

I started checking the postmaster@wfu.edu mail.

First I asked people on SAGE’s (members-only) listserv whether they check their postmaster mail. The response was an overwhelming “some human must read this mail.”

A few hours later, I got Thunderbird set up with some rules, like “immediately delete any mail from MAILER-DAEMON where the subject contains ‘user unknown’”.

The problem is, lots of people have OOO (out of office) messages, which (probably despite some RFC) reply to postmaster. Those aren’t easy to filter, but so far there have just been 5-10 a day, so I can delete them. There are also some noisy cron jobs, but only once per day and only a few messages.

Lo and behold, I got the first legitimate message yesterday, from someone who thought they got spam from us. The mail headers were forged, actually (the spammer used a WFU address but mail really came from another place) so I let them know.

Randal Schwartz’s excellent columns tipped me off to DProf a few months ago. Basically, if you have code that runs for a long time, you execute it like so:

sh% perl -d:DProf program.pl

Then, when it’s done, run

sh% dprofpp

The 15 subroutines that took the most (exclusive) time will be displayed. It’s neat, because I could use it to shave 15 seconds (50%) off the running time of a program.

Every day, I feel more like I need to learn about SNMP. It stands for “simple network management protocol” and is supposed to let you monitor and even interact with machines. You can get emailed and traps can be sent depending on what’s going on.