Brett Sheffield . com

We’ve had a couple of customers who want to be aggressive on spam, *but* don’t want to risk losing any business emails, however broken the mailserver that it originates from.

The oil industry seem to be particularly bad, and having two marketing companies using our service and a chain of casinos also make for fun times when using various filters.

A couple of months ago I implemented some tighter spam controls. Basically, enforcing the RFCs a bit more tightly because we know spammers take short-cuts. Most of these controls are still in place, but I’ve had to exempt several of our customers due to complaints that email wasn’t getting through. It seems it’s not just spammers that take short-cuts - there are a lot of amateur mail admins out there, and we’re not just talking cowboys who’ve thrown an M$ Exchange server in without taking it out of its cellophane. We’re talking BIG companies (lots in the oil industry), technical companies, all sorts.

You’d think being strict with enforcing RFCs would be reasonably safe, but I’ve lost count of the number of mailservers that don’t have a postmaster address set up, that send from invalid addresses, don’t have reverse IP resolution set up etc. etc. etc. These are really good ways to catch out spammers at smtp time, but from time to time it catches a real email and I’m tired of explaining to customers that it’s the other guy’s mailserver that’s broken.

Many email RFCs have been broken, bent and ignored for so long that suddenly enforcing them breaks things.

Rejecting mail at SMTP time is the “right” way to do things. It reduces bandwidth, memory, cpu and disk usage and eliminates backscatter. In a large ISP the two main costs are power and bandwidth, and so there are real cost savings to be made by enforcing RFCs at SMTP time. It’s even good for the environment. By ruthlessly checking for a postmaster address I know that while I sit at my keyboard here, I’m doing my bit for the polar ice caps.

By fortunate coincidence, the most problematic of our clients *only* receive email from UK companies + a couple of known addresses that we can whitelist individually. So, if we could whitelist *everything* from the UK as well, we’d be pretty sure of not missing and valuable emails.

I’ve taken an old script of Dan Shearer’s (thanks Dan) for grabbing the IP ranges from RIPE, APNIC, AFRINIC, ARIN & LACNIC, updated it and hacked it around so it spits out zone files suitable for use with rbldnsd. If anyone else wants to make use of it, feel free. http://georbl.info/

Google PageRank is a live animal. Google Toolbar PageRank is not. Toolbar rank is updated approximately every three to four months. Today appears to be the day. Yesterday this site had a PageRank of 0/10, today it’s leapt to 3/10. It was about due. The last update was around September 2006. The website of my open source hosted applications business, Gladserv, which was launched a month ago, has jumped from nothing to 3/10 also.

There were other clues. I monitor the PageRank of sites under my control fairly carefully. None had changed at all in months. I was reading an article about PageRank updates yesterday which mentioned the PageRank checker: ezer.com. I’ve tried a few of these kind of sites before, and most of them are rubbish. Yesterday ezer showed mostly 0/10 for this site, with a few 3/10’s. Today it’s showing mostly threes and a couple of zeros. I guess the propagation of this update is almost complete.

My former software and web design business, Gladsoft (Gladsoft is dead! Long live Gladsoft!) has fallen off the PageRank charts completely. About time. For six months last year I had it displaying the apache test page. Late last year, as it still had a PageRank of 4/10, I decided to make it useful. I was still getting a large number of enquiries from people looking for web design services, so I put some Google ads up and a few links to companies I’ve dealt with that might be able to help them. Share the PageRank love, that sort of thing. There are still a good few sites out there linking to it, so I imagine it will resurrect itself Googlewise next time there’s an update.

I notice Google has picked up this blog recently so I guess I’d better start writing in it. Drafts of various articles have been underway for a while, but I’ve had little time to finish them. I expect I’ll be writing more over the Christmas break. Last year I spent considerable time testing and reviewing Open Source LAMP apps between eating various roasted animals and consuming vast quantities of alcohol. Bliss.

Gladserv.com is a step or two closer to being launched as a business hosted services provider. The domains are registered, the website is coming together, the second dedicated server has been ordered from Bytemark. An earlier order from UK2 was aborted when I discovered just how difficult they were to contact. Take a look at “Why Not To Use UK2” if you’re seriously considering them - cheap has more than one meaning. This server will be split into several virtual machines (VMs) using Xen with unused VMs sold off - there are already three other businesses on board.

I went to see the bank yesterday and my bank manager actually told me he thought my revenue estimates for the first year were very conservative. I tend to estimate on the side of caution these days, after previous bitter experience. This project is definitely gathering momentum.

I’m starting to promote the site. At the speed Google moves, I think it best to link first and write afterwards. I’ve put the shell of the site together using Website Baker, which is probably the easiest Content Management System (CMS) to set up and use I’ve come across. Graphics and pretty stuff will follow when someone with more visual talent than I provides them.

For the moment I have no need for the kind of fancy frippery that something like Joomla has built in. I usually spend the first hour on a new Joomla site turning everything off. For a simple business site, Website Baker has everything needed to get off the ground without additional distractions. There are some addons available to perform most commonly required functions, but nothing like the bewildering range of Joomla toys. Maybe later.

Yesterday I bought an incoming phone number from Gradwell and pointed it at an old Asterisk installation on my backup server. I’ve never used Gradwell for VOIP services before, but they came highly recommended to me so I thought I’d try them out. I’ve had less success with some other providers in the past. No problems at all so far. Online signup was straightforward. At one point I needed to phone for an authorisation code. At 1730 they answered the phone within a few rings and dealt with it on the spot. Provisioning of the line was immediate.

Asterisk setup is a topic for another day, but to add a new number into an existing setup is trivial. Add a few lines like this to iax.conf:

[08708618861]
type=user
username=myusername
secret=mypassword
context=iax-in
host=dynamic

and a line in extension.conf to tell asterisk where to direct incoming calls:

[iax-in]
exten => 08708618861,1,Goto(gladserv,s,1)

Easy. No need to get a man in at all.