Frequently Asked Questions

Mail Filtering FAQ

Does Blue One filter my e-mail?
Why does Blue One filter my e-mail?
What is Spam?
How do Spammers get e-mail addresses?
How does my e-mail get filtered?
What are Realtime Blackhole Lists?
How do Realtime Blackhole Lists work?
What is an Open Relay Mail Server?
Why is having an Open Relay Mail Server bad?
What is the error a blocked mail server would receive?
I host my own mail server and get the bounced back messages, what can I do?
Where can I get more information?

Q. Does Blue One filter my e-mail?
A. Yes.

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Q. Why does Blue One filter my e-mail?
A. To prevent Spam e-mail from being sent to Blue One customers.

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Q. What is Spam?
A. Spam is the "junk mail" of the Internet. It is unsolicited, meaning the recipients did not sign up for the e-mail but received it anyhow.

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Q. How do Spammers get e-mail addresses?
A. There are a number of ways that an e-mail address can fall into the hands of a Spammer. Lists of e-mail addresses can be purchased, just like many bulk mailing companies purchase lists of people's addresses. Giving out your e-mail address through a form on a webpage is another way, as is going into chat rooms on the Internet. In some cases, Spammers have gotten ahold of e-mail addresses by looking in the "From" field of a forwarded message, which often contains the e-mail addresses of everyone who has received the message.

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Q. How does my e-mail get filtered?
A. Blue One is provided with lists of mail servers from around the world that have been known to send Spam e-mail. These lists are often refered to as Realtime Blackhole Lists. When mail is sent to our servers, the incoming messages are only blocked if they originate from a server that shows up on one of the Realtime Blackhole Lists that Blue One is provided with.

When the blocked server tries to connect with Blue One's mail server, we prevent them from sending us mail right then, in addition to sending back an error message that we will not accept mail from the "black listed" server. The blocked messages are bounced back to the sender by the black listed server along with the error message that we provide. Blocked messages are never deleted by our servers. You may still send mail to servers that are on the Realtime Blackhole Lists.

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Q. What are Realtime Blackhole Lists (RBLs)
A. Realtime Blackhole Lists (RBLs) have the IP addresses of e-mail servers that have been known to send Spam. Most of the Spamming mail servers are a type of server called an Open Relay Mail Server. These lists of "black listed" mail servers are provided by a number of mostly nonprofit organizations that are committed to ridding the Internet of Spam.

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Q. How do Realtime Blackhole Lists work?
A. The organizations that compile the lists use a special web search tool that looks at e-mail servers to see if it is an Open Relay Mail Server. The organizations also research which of those mail servers send Spam, either on purpose, or because other people can "high jack" the mail server to send Spam.

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Q. What is an Open Relay Mail Server?
A. Open Relay Mail Servers allow anyone from anywhere in the world, connected to the Internet by any means, to send mail through a mail server without having an e-mail account, or any other company or customer account with the mail server.

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Q. Why is having an Open Relay Mail Server bad?
A. Spammers are the ones who most use other servers to send mail, but Open Relay Mail Servers can also be used to spread computer viruses. Spammers do not own the servers they send most of their mail through, nor do they contribute any money or labor to the upkeep of the servers. This amounts to theft and is sometimes called "high-jacking" the server. Not only does the Spammer use a piece of equipment that is not theirs, but they also hog network resources as the massive amounts of mail sent through the servers require processing time and bandwidth.

Many of the stories you have heard or read about "Denial of Service Attacks" are Spammers who use a company's mail server to mass e-mail the Internet. So much mail is sent through at once that the mail server finally crashes, disrupting a service that others pay for. And mail sent through Open Relay Mail Servers is largely untraceable, so even if you detect that your mail server has been used to Spam people, your chances of catching the person or people responsible is slim to none.

Not all Open Relay Mail Servers are guilty of sending Spam, but the potential is there.

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Q. What is the error a blocked mail server would receive?
A. TO: email@address.com [550 Open Relay Detected, Msg Blocked, See http://relays.osirusoft.com/]

This is an example of the error message that Blue One sends back with the blocked messages. The error will appear in a message that is bounced back from the black listed server to the original sender, along with the contents of the sender's original e-mail.

The last part of the error message displays which Realtime Blackhole List or lists that the mail server is on and gives a web address that people can visit to get more information. People who get this error message need to contact their Internet Service Provider or their network administrator to have the problem cleared up.

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Q. I host my own mail server and get the bounced back messages, what can I do?
A. If you have a Domain Hosting account with Blue One and repeatedly get bounced-back messages saying that your mail could not be delivered because it was rejected due to it being on an RBL, your mail server could still be configured for Open Relay. Even if you do not participate in sending Spam yourself, you may be a victim of someone using your server to send mail without your permission. Relays.osirusoft.com has a search page that allows you to enter the IP address of your mail server and search their database to see if your mail server is on the "blocked" list.

To find out what IP address your mail server has, follow the instructions below:

1. Click on your Start button.
2. Click on Run.
3. Type command and click the OK button.
4. A black screen should open up, that is the Command Screen. Type ping mail.yourdomain.xxx and hit the Enter key on your keyboard. Replace the word yourdomain with the domain name that you have registered with Blue One and replace the three x's with the proper suffix (com, net, org...). The IP address of your mail server will appear in [straightedge brackets] and will be a series of four numbers separated by periods (Ex: 209.42.162.71). When you want to close the Command Screen, type exit and hit your Enter key.

Now that you have the IP address of your mail server, go to http://relays.osirusoft.com/cgi-bin/rbcheck.cgi to find out if your mail server is being blocked. If it is, you will need to disable and/or get rid of Open Relay on your server. After you have disabled or uninstalled Open Relay from your mail server, you will need to visit www.mail-abuse.org and http://relays.osirusoft.com, or any other Realtime Blackhole List that your server may be on and report that your mail server has been protected against Spammers and to take your mail server off their list.

The Realtime Blackhole List will then test your server again to make sure it is a Closed Relay Mail Server, and if indeed it is, the IP address of your mail server will be taken off their list.

For advice on how to fix an Open Relay problem, visit http://mail-abuse.org/tsi/ar-fix.html.

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Q. Where can I get more information?
A. http://www.mail-abuse.org
http://www.mail-abuse.org/rss/.
http://mail-abuse.org/tsi/ar-what.html
For a more technical explanation of Open Relay Mail Servers, the affects and cures, read the information gathered by the UNIX Workstation Support Group at Indiana University.

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