Mail Relay Blackholes to cut down on spam

This is targetted for email senders whose legitimate email has bounced with a message directing them to this page. ISPs whose customers have complained to them can find out how fix their problems on the open relay page.

Why do you use blackholes?

Clarke Computer's servers use various means to combat spam. One of these is the use of databases of open relays, dialups and other spam sources. By not accepting email from sources within these databases, we have managed to reduce spam by about 75%. Unfortunately, a lot of spam still gets through. Our customers have asked us to do more to cut down on this spam. As a result, we have decided on a policy that will bounce email from some innocent/legitimate people to both cut down further on the spam and also to educate those people about the problems with their ISP.

Since spam isn't like junk snail mail where the sender bears the majority of the costs, but instead costs the receipient time and money for bandwidth(and possibly disk space), we hope that these measures help move the cost burden back to the ISPs that are lenient on or encourage spammers and therefore back to the spammers themselves.

To do this, we hope to increase our use of blackhole databases until we have received comments from our customers about end users who haven't been able to reach them.

My email bounced and the message directed me here!

If you've bothered to come here, you are probably an innocent user. The reason your mail bounced is that there has been a problem with spam, aka. UCE (unsolicited commercial email), from the server you are using to send email and so the server has been placed in a blackhole database. For the reasons stated above, we use several of these databases and thus won't accept mail from your server which has been identified as a source of spam.

Even if we allowed email from known sources of spam, others still wouldn't and so you would run into this problem earlier or later. We figured it would be best for you to make a conscious choice knowing the problems your ISP has and possibly vote with your checkbook by moving to another ISP where you won't have problems sending email.

Look at how to workaround this problem at what steps to take to get your ISP to fix this problem.

How can I work around this?

Because it is your ISP which has a problem, you can get a free account at some place like Hotmail or Yahoo and send the email from there. Because of the potentialfor abuse(and past abuses), the free webmail accounts have better spam prevention policies than some ISPs.

This will allow you to send email to any of those who are blocking your ISP.

What steps should I take to get this fixed?

First, look at the bounce to see which database was used to bounce your email. Only the first database that would have bounced your email will be shown. After having your ISP fix their problem and contacting the appropriate database to recheck, you may still get a bounce from another database.

Each bounce will have an abbreviation appended to it. If you don't see that abbreviation below, email us, including the bounce message, because we must have added a database to the mail server and missed adding it here.

  1. Find that abbreviation in the bounce notification.
  2. Look at the full headers for your bounced email and figure out what the machine was that was trying to contact our server and that was blackholed.
  3. Go to the database's web site and see why that machine is blackholed.
  4. Notify your ISP of the blackhole, the machine involved and the reason why. Ask them what to fix the problem.
  5. If your ISP won't fix the problem, switch ISPs and tell your old ISP why. It may take them losing more money from innocent customers switching than they make from the spammers for them to make changes.
  6. Be proud that you have taken steps to reduce spam.

My ISP won't fix this, how do I find a new one?

If you can find a local ISP on the Responsible Anti-spam Sites list, then you can probably just use them.

If not, you are probably in for a bit of work.

First you need to determine the likely mail servers for the ISP that your mail would go through to the outside world. You can ask friends who use the ISP, the ISP or go with the likely servers. The likely servers are mail.ISPNAME and the servers listed as Mail eXchangers(MXes) for the ISP. If you have access to nslookup, you can find the mail exchangers by doing a nslookup -type=MX ISPNAME. Large ISPs may have local mail servers that you actually send email through that aren't listed as MXes for the ISP.

Next, you need to find the IP address for each of these mail servers. nslookup MAILSERVER and ping MAILSERVER will give you the IP address.

Then go to the lists and check to see if that IP address is on a list. If none of the mail servers are on any of the lists, then the ISP is probably good.

If anyone wants to fund the creation of a CGI to automatically check an ISP for you, please let me know.

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