Spam is a problem. We’ve all experienced it, our inboxes clogged with it, training spam filters to try and keep up with the ever more creative ways of misspelling various pharmaceuticals. We’re always on the lookout for a better way to block it. But have you ever been on the other end of that fight?
Well now I have. No, I wasn’t sending spam. Nor was I even the victim of a hacking attack that sent out spam. No sir, my crime was much more mundane: debugging emails. While trying out ReadFeeder’s new update algorithm, I had cron sending me regular reports at the end of each run. Every 10 minutes. But that’s 6 emails an hour, that’s not a problem is it?
Well it turns out it is. Not because of the number of emails though, but rather because of the source of those emails. See, spammers can’t exactly set up shop at a permanent location, otherwise they’ll get blocked in short order, so they tend to look for more dynamic solutions, and something like Amazon’s EC2 or other automated hosting services fit that bill. In order to prevent them from using these services to dump ads into our collective tubes, spam filters have been blocking emails coming from dynamically allocated host IP addresses.
But ReadFeeder.net needs to send emails, not just cron output to me, but registration information new beta testers. It just wouldn’t do to have those emails falling into spam traps and never reaching their intended users. The solution, as I found out, is to use a “smart host”, another email server that isn’t on a dynamic IP address. Most of us do this all the time, we send email through our ISP’s email servers rather than directly to our recipient’s email server. Since I registered ReadFeeder.net with Google Apps, I was able to tell Postfix to send outbound emails through Google’s mail servers first, which required that I authenticated over an encrypted connection.
There are a couple dozen results for a search of “use google apps as smarthost for postfix”, and all of them have slightly different configurations, none of which worked exactly for me. I’d post mine, but I’m pretty sure it wouldn’t work exactly for you either, so I’d just be adding to the noise. But if you’re trying to get a similar setup and can’t quite make it work, send me an email or reply to this post.
Oh, and if you signed up for the Beta program and haven’t gotten an email letting you know how to get started using it, please let me know, because it’s likely that email got caught in a spam filter somewhere, and I will have to resend it to you.