Nate's Programming Blog

Ever since I renewed my domain name and restored my blog and wiki, I have been playing around with a variety of services on my server. One of those services was setting up a secure e-mail server. It took me awhile to get postfix configured correctly to use TLS and SSL, but eventually I got it working. Once I had it up and running, I tried sending myself some test e-mails to my gmail account and noticed that all of the traffic was going straight to the spam folder. After doing some research, I learned a lot about the techniques e-mail servers use to determine whether an e-mail is spam or not. First I needed to make sure that my MX records were set correctly on my domain provider’s domain server. I added one additional entry for the base domain “natesprogramming.com”, but other than that, I had already set everything up correctly.

Then I needed to setup an SPF record. Luckily my domain provider provided an easy wizard for setting that up. I checked it by e-mailing my gmail account and opening up the details on the e-mail message and saw that the SPF passed.

The one issue that I ran into that I didn’t have a real good fix for, was the forward-confirmed reverse DNS. This required me to change the record on the DNS server of the owner of the IP address. Unfortunately that is not really an option with my ISP, so to try and get around this, I changed my hostname on the server to match the domain for nslookup . Now e-mails are no longer going straight to the spam folder on my gmail account. I also checked with my girlfriend’s yahoo account and it appears to be going to the inbox there as well.

In the process of doing all of this, I now have a much better understanding of how spam filters work and typical tactics of spammers, so if I ever need to setup an e-mail server again, I know what to do 🙂