WHY DO I CARE IF A
SERVER IS LISTED
AS AN OPEN RELAY?
So a server is listed as an open relay. So what? How does this affect you? This depends on if this is your server, and/or if you're expecting to receive mail from this server.
If your mail
server is listed as an open relay, then any mail sent from your server by you or
users on your network will be actively refused by any server on the internet
that uses these databases. As of 3pm on July 15th 2002, our server is one
of those servers.
If you are not receiving mail from a particular network, it
is likely their server is listed as an open relay or an open proxy and our
server is refusing connections. Perform the lookup on the previous page
(click the Back button in your browser or click HERE
to go directly there if you linked to this page directly) to determine if this
is the case. We actively subscribe to the following databases:
relays.ordb.org
bl.spamcop.net
relays.osirusoft.com
relays.visi.com
If a server is listed in one of the above databases, users on our network will not receive mail from that server until it is removed from the list.
IMPORTANT
NOTE:
It is imperative to understand that
it is *not* ACD.net's responsibility if a remote server is blocked by our
server. The only reason mail will be blocked is if the following criteria
are met:
- The
remote server's security is compromised and/or misconfigured.
- Spammers have exploited this compromise and have sent mail using this server.
- Users on the internet have reported the abuse of this server.
- The server has been tested by anti-relaying authorities and confirmed as an
open relay/proxy.
It is *not* ACD.net's responsibility to monitor or review the security of remote servers. This responsibility falls solely upon the administrator of the mail server being blocked. By the same token, ACD.net *is* responsible for our own server becoming blocked. Also, when customers on our network have their own mail servers (such as business DSL or T1 customers) and find themselves on these lists we take action and inform them (generally we receive abuse complaints regarding spam originating from our network), but the customers themselves are ultimately responsible for remedying the situation and informing whoever is blocking them to retest their server. In some cases--depending on the severity and frequency of the abuse--we are required to deactivate our customer's connection until they can resolve the issue. Failure on our part to do so may result in all of our network (our server included) being blocked due to the misconfiguration on one of our customer's servers This makes our entire network suffer.
Essentially this means if you routinely receive mail from a particular user, and as of July 15th you haven't been able to, they're probably blocked. Find out what server they're using to send their mail, and perform a lookup on it. If it is listed, they need to contact their mail administrator and inform them of the problem. ACD.net only blocks mail listed in the above databases, so if we're blocking it, other networks are, too.
So how do spammers find these servers? It's pretty simple, really. Almost anybody with a high-speed internet connection and personal firewall software has probably been probed--or port-scanned--at one point or another. Spammers use port-scanning software to locate mail servers on the internet. Port-scanning software goes through thousands of different IP addresses and finds what computers are doing what. It will find web servers, FTP servers, mail servers, etc.,. When mail servers are found, the spammer tries to send mail using that server to some email account somewhere, like yahoo.com or hotmail.com. If the message is received successfully, that server is an open relay, and is now the spammer's best friend. If the server rejects the message (or accepts it but just drops it and doesn't deliver it onward) the spammer grunts in disgust and moves on to the next mail server, cursing the mail administrator of that server for having the foresight to secure their server against such abuse.
Remember, boys and girls: if you're a mail administrator, the power is in your hands.