Significant Backscatter

Experienced my first significant backscatter on one of my domains today. Good times.

Here’s how backscatter happens:

  1. spammer forges the sender in email, such as ‘From: NameGeneratedBySpammersEvilSoftware@example.com’;
  2. server which receives the forged email bounces the message;
  3. since the spammer used my domain as the sender, the bounce comes to my domain;
  4. since the spammer guessed a name that doesn’t actually exist, my mail server is unable to deliver the bounce message locally (generating a double bounce);
  5. my mailserver then sends the double bounce to postmaster at my domain; since I’m the postmaster, it sucks to be me.

Over a 5-hour period, I received 1200 of these little messages.

Some of this is caused by my use of qmail. Qmail will accept a message for delivery at the SMTP stage, then realizes there is no suitable recipient. At that point it has to generate a bounce and return it to the sender — who was forged, creating a double bounce.

Might become necessary to install chkuser — it refuses to accept email unless there is an actual recipient. We’ll see. At the moment, the rate of backscatter has dropped to a few per hour.

First Day of Preschool

First Day of Preschool

Today was Alice’s first day of Preschool. She’s enrolled in the 8:45-11:00 classes on Tuesday and Thursday every week at Copperfield Preschool.

We’re very close to the preschool, so Alice, Mommy and I walked together. Alice wore her Backyardigans backpack (she had to carry her indoor shoes, don’t you know).

Ready to go!

It was only a 10 minute walk. When we got there, it was pretty chaotic. Lots of concerned parents, lots of upset toddlers.

Alice was pretty calm about the whole thing. She’s been going to Donna’s for over a year now, so she’s seen her fair share of children learning to adjust to a new situation.

Mommy changed Alice into her indoor shoes and we hustled her into the play area. We then quickly made our exit, so nobody would become upset.

Because we didn’t know we were supposed to bring a snack for Alice, I dropped one off on my way to work. I was very discrete, so Alice didn’t know I was there. She was sitting quietly with all the other kids as they gathered around one of the teachers — I think it was story time. Alice was not upset at all, but many of the other kids were crying.

Alice had a good time at preschool, then she and Mommy came to meet me for lunch.

Tonight when I was putting Alice to bed, I told her to take a look at her dreamcatcher. Her cousin Zach made it for her, to help her have good dreams.

“Have a look at your dreamcatcher, Alice. It will help you only have good dreams.”

Alice took a look, then nestled back into her bed with all her blankets and pillows.

“What are you going to dream about, sweetheart?”

“School.”

How precious is that?

Passed My RHCE Exam

I received the results from my RHCE exam — they arrived in my inbox Friday night.

  • Section I: Troubleshooting and System Maintenance
    • Compulsory: 50/50
    • Non-compulsory: 50/50
    • Overall Section I score: 100
  • Section II: Installation and Configuration
    • RHCT Components: 93.5/100
    • RHCE Components: 100/100

My marks were much higher this time. Three more years of experience helped, but it was probably more important that I wasn’t a sleep-deprived father of a 7-week-old baby girl. It also helped that I had my IBM R51 with CentOS 5 — this was indispensable when I was studying.
RHCE Certificate number: 805007524928180
RHCE Certificate (PDF)