The Littlest Things

Wednesday, June 20, 2007, at 07:22AM

By Eric Richardson

I've been having a problem lately sending some random emails. They simply wouldn't go out. qmail would tell me:

 deferral: Sorry,_I_wasn't_able_to_establish_an_SMTP_connection.

Trying to telnet to port 25 on the receiving mail host would simply time out, unable to connect. From a different host it would work perfectly.

Finally today I got fed up, prepared to think this was something I just wasn't going to solve. I was almost ready to try routing my outgoing mail through a different host when I saw something a little funny. In my routing table I had an incorrect route that was sending 66.0/8 out via eth0 with no gateway. I ran some queries and sure enough, all the hosts I couldn't connect to were 66.x.x.x.

One simple:

sudo /sbin/route del -net 66.0.0.0/8

and everything was working.

Eric Richardson lives in Atlanta, Georgia, where he works on payments infrastructure for Cash App.

Past lives involved streaming audio for Southern California Public Radio, running a hyperlocal news site for Downtown Los Angeles, working on custom mapping code, and writing Perl at the Jet Propulsion Labratory.

Previously on this date...

2005
Field Trip
So I had to take a field trip today for my Geology class. I wasn't excited about it, since it meant a good long while in a bus. We left USC at 8am...
2002
cell phones
I really know more than most people should about cell phones. Everyone else just cares about making and receiving calls, and here I am looking at things...
2001
more bar graphs
I've now completed evolving my bar graph code into a Perl module that works generically for any data. Witness two example outputs: test3 and test4.
2000
richardsons on the web
I was sitting around here today, waiting for a tape to record, just wandering around the web. On a whim, I decided to see who else in the world had a...