This morning running the update everything looked fine and working. But email traffic looked a little on the light side, I didn’t even receive any spam. So I started looking around for any issues that mifght have happend and I couldn’t find it. When looking at the server it was blocking port 25 but from the servier itself all looked fine. So naturally I blamed the firewall, but that wasn’t it.
Then I read the information on the Security Update and there was an item on postfix there:
Available for: Mac OS X v10.5.5
Impact: A remote attacker may be able to send mail directly to local users
Description: An issue exists in the Postfix configuration files. For a period of one minute after a local command-line tool sends mail, postfix is accessible from the network. During this time, a remote entity who could connect to the SMTP port may send mail to local users and otherwise use the SMTP protocol. This issue does not cause the system to be an open mail relay. This issue is addressed by modifying the Postfix configuration to prevent SMTP connections from remote machines. This issue does not affect systems prior to Mac OS X v10.5 and does not affect Mac OS X Server. Credit to Pelle Johansson for reporting this issue.
I checked the configuration files and I noticed, by the date, that main.cf was changed. I did a diff with a backup and I founf out that the security update added the following line:
This means that only local programs get access to the postfix program. This was the cause of the problem of no longer receiving any mail! So I removed the line from main.cf and restarted postfix with the command:
Because of the startup scripts postfix will restart automatically.
By the way, I also noted this error message in the logfile:
I’m not sure this is due to the Security update but it means that postfix is unable to access mysql because support for it wasn’t compiled in. You can check it by running:
It should return mysql in the list. It wasn’t on my computer. To solve this I went into the postfix source directoy of the last succesfull build and ran a:
Restarted postfix again and all was fine and running again. I also received some spam today. Please leave a comment if you see this on your system as well.