Great Ideas in the History of Sun Java System Messaging Server, Vol. I
By joesciallo on Dec 18, 2006
We're all taught in school and in business, no question is a dumb question. It's just that some of the ideas we get might be not so brilliant to begin with. One needs to fully understand the situation before getting into trouble with one's brilliant ideas.
Take for example, the idea that crops up every now and then in the Messaging Server world of disabling the SMTP banner to not show the server name and the version of the application that is running. On the surface, this sounds like a good request, one to ensure more system security. After all, one can't be to concerned about security.
However, let's break this down a bit.
Messaging Server does not support not returning a server name because it is contrary to the SMTP standard. Not returning the SMTP banner causes all sorts of problems with lost or bounced mail. (See RFC 2821 for more information.)
Now, if you want to change the server name that's returned, you can use the BANNER_HOST TCP channel option. Furthermore, you can change the additional information that is returned by setting the CUSTOM_VERSION_STRING TCP channel option.
But perhaps the best thing to do before embarking on such a course is to understand that not returning the SMTP banner makes a site less secure and not more secure. A recommended read before doing anything is Bruce Schneier:
As with most things in administering a complex environment (and in life), doing your homework first will save you a lot of headaches later.
Stay tuned for more "Great Ideas in the History of Sun Java System Messaging Server."