Open Mail Relay?

[sfleming]

I have received an email from someplace called the Open Relay Database (www.ordb.org) stating that my Mac OS X Server machine is an open relay. Obviously, that's a Bad Thing.

I am running SMTP (not sendmail) and, in Server Admin, I have the checkbox marked next to 'Deliver mail to local addresses only (no SMTP relay)'. Beyond that, I don't know what to do. Any suggestions? Thanks!

Stephen Fleming

[mervTormel]

just because your server IP is in there database, doesn't make it necessarily accurate.

you should validate their claim, and if it's false, get out of their database.

[Craig R. Arko]

Read this article (http://docs.info.apple.com/article.html?artnum=106762) and a couple of (linked) related ones in the Apple Knowledge Base.

You need to add a couple values to the NetInfo database.

[therabidpenguin]

You should also be able to close this by requiring all users to be authenticated when sending email.

[gdsgds]

Well by default the mail server bundled with OS X Server acts as an open relay. Take a look at KB Artciles 106762 & 106763 (106760 & 106761 are of interest too). But be also sure to check your built in firewall rules. Also remove the "deliver to local address" option this will prevent to external mail to be delivered to the recipient.

Make a lot of tests because it's really needs to be fine tuned.