SMTP relays and stopping spam

ninjaz

They talked about this in one of the books that I have and I didn't pay much attention to it because I didn't think that it was going to be a question that I was going to see on the test. Well, to my surprise it was on the test and I know I missed the question. I have been going through my books now trying to find it and I cannot find it anywhere.

The question is: Something about placing a period or an astric with a forward slash in the config file to stop relaying of messages. I know that there are black lists out there that block domains from sending messages but this was real specific to placing one of those puncutions (period, *, / or /) at the bottom or the top. Any ideas?

Webmaster

I didn't have a question regarding mail relays on my exam, but I think this refers to the allowed domains. By default, some systems allow relaying for all domain, which is denoted by an * (as in wildcard). You can remove the * or replace it with specific domains to restrict relaying.

For more general info about email security:
www.techexams.net/technotes/securityplus/emailsecurity.shtml

RussS

Ahhh how we so easily make mistakes on things we feel will/will not be in the test

The number of open relays out there is frightening - the evidence is the quantity of spam we recieve daily - unless of course you have a good spam trap

ninjaz

I came across it again in one of my practice exams. The question is:
"You are a network administrator. What happens when you restart your email , after deleting a "." entry in a relay domains file?"
Answer:
"You prevent relaying of non-explicitly named domains."

Can someone explain this a little better?
Thanks

seuss_ssues

forgive me if im inaccurate but email servers is something that i have not messed with


When you have an email server it can be used to relay messages, but unfortunately many spammers use this ability to make it seem as thought their spam is not comming from them but rather from you, so there are configuration files that let you specify which hosts are allowed to use you as a email relay server.

the contents of the file may vary depending on the server you have running but it probably allows single entries of hosts and also wildcards that dicate that "*" all hosts may you use as a relay or "." no host may use you as a relay


Id really appreciate if someone would back me up on this or elaborate further, i did not look any of this up but rather was going off the top of my head and i have never worked with email servers so anyone looking at this message needs to research further or wait for further confirmation on this thread.