The URL of this page is http://forum.spamcop.net/forums/index.php?showtopic=972
Why Am I Blocked? Probable Causes
If your email has suddenly been blocked by the SpamCop blocklist, it is probably because you share an IP address with other email users and there is someone who:
- is using auto-responses that are replying to spam with forged spamtrap email
addresses (such as Out-of-Office/Vacation notices, virus notifications, and 'bounces' created after accepting the email);
- has a computer with a virus that sends spam without the owner's knowledge;
- has a computer that has been compromised and spammers are remotely controlling it to transmit their spew;
- is sending unsolicited emails and your internet service provider is allowing it;
- or because, as in all systems, there may have been a mistake. (very rare)
Click here to jump to the section For people NOT in charge of running an e-mail server
For people who are operating servers:
Am I really listed in the SpamCop Blocklist?:
You can check the status of any server by entering its address at http://www.spamcop.net/bl.shtml. The reason an IP address is listed can also be obtained from that page.
If the blocklist only lists spamtraps, then the likely culprits are auto-responders or misdirected bounces (that is, bounce emails sent after acceptance of the email instead of being rejected by the server during the SMTP phase, which would include emails such as "no such user", "non-existent mailbox", and/or "quota exceeded").
If the blocklist only lists reports, you have a spammer at work.
If the blocklist lists spam traps and reports,
- You have your firewall configured to allow a compromised machine on your network to spew to the world
(you do have a firewall in place, don't you?)
- the SMTP/Auth exploit of an Exchange server is in progress, see these links:
How To Block Open SMTP Relaying and Clean Up Exchange Server SMTP Queues
To prevent SMTP relaying with Microsoft Exchange Server
(NOTE: While commonly seen on Exchange servers, this condition is possible on all platforms)
- Your PHP mailer program has been taken over by criminals.
(You did not know that your PHP bulletin board had a very vulnerable mailer program on it?)
((You did not know that you had PHP installed and running?))
- How can I get removed from SpamCop's blocking system?
- John's explanation at John's revised post, for Why Am I Blocked FAQ
- Merlyn's explanation at FAQ Entry: Why is my email blocked?
The rest of this FAQ is for people who do not run servers.
For people whose email was returned
Q: What does SpamCop do with my email? A: Nothing
The Internet Service Provider (ISP) of the person, or business, you are sending email "To" is blocking email from your ISP's computers (servers), using a list provided by SpamCop.
Your email doesn't pass through SpamCop's mail servers and SpamCop has no way of blocking or bouncing your email.
In addition, the SpamCop email service uses the blocklist to "tag" incoming mail so that suspected spam is placed in a particular folder and that is the way the blocklist is intended to be used.
Q: What is a blocklist? A: A blocklist helps ISP's to prevent spam coming to their customers.
An ISP can use a blocklist (a list of IP addresses),to block (Reject) all email coming from a particular IP address. This rejection will cause your ISP to send you what is called a "bounce" message
The blocking is based not on your email address (which looks like username[at]example.com), but on the IP address (which looks like 18.104.22.168).
This IP address is assigned to the mail server you use, which is probably run by your ISP. You may share this same server with hundreds or thousands of other customers. If one of the other customers is sending spam through that shared mail server, it will cause the IP address of that mail server to be put on the blocklist. And when you send email through that server, ISP's who use blocklists to avoid receiving spam, will also block your email.
SpamCop is one of many blocklists. DNS Blackhole Lists (DNSBLs) is a link to page that lists and categorizes a number of blocklists. Trying to describe the difference between spamcop & other lists (particularly the time it takes to get off the list) and how SpamCop can be an early warning system for ISP's is a bit difficult, as each is different in concept, targets, results ranges, and oversight. If more specific data is desired on other DNSBLs, please visit that listing site.
Q: What is SpamCop? A: Unique, automated blocklist and spam filtering
SpamCop has a program that will try to find the correct address to send a complaint because the email address you see that says who it is from is often forged by spammers. SpamCop uses the information in public internet databases that ISPs are supposed to put the correct information in to find the proper address and forwards complaints for its members. If a lot of reports are made, the IP address goes on the SpamCop blocklist that is used by many ISP's. for more detailed information on how Spamcop works see: http://www.spamcop.net/fom-serve/cache/3.html
Q: How do ISP's use SpamCop A: As 1) a warning that spammers have slipped by their defenses and 2) to block spam.
1) Responsible ISP's welcome SpamCop reports and will remove spammers quickly from their systems.
2)When they block emails, they send a message that looks like this:
451 Blocked - see http://www.spamcop.net/bl.shtml?xxxx.xxxx.xxxx.xxxx:
email from xxx.com blocked,refused by Spamcop,see http://www.spamcop.net
Q: Why me? A: It Happens to the best of us
It is annoying to have your email blocked. It is also annoying to have a backhoe interrupt email service.
However, until the blocking problem is resolved, you can email people through a web based email service (the most familiar web based email services are hotmail and yahoo).
After you have taken care of the immediate problem of being able to communicate with someone by email, the next step is to see what can be done so this inconvenience does not happen to you again.
The one thing you do not want to do is to complain to those correspondents who are using an email service that uses the SpamCop blocklist. They probably really like the reduction in spam!
You have the responsibility to see that your ISP provides you with reliable email service.
See this link for a longer explanation of costs http://forum.spamcop.net/forums/index.php?showtopic=660
Q: Who do I contact to correct this problem? A: Your ISP (email service provider) first
Usually the ISP with the blocked IP address has also been notified with the evidence of spam reports. Your ISP may have already acted on the Spamcop report they have received by the time you call. It may just have been a mistake on their part or, possibly, the reporter's part. Reporters can be fined or banned for mistakes.
As soon as your ISP stops the spam from being sent, or uses the procedures at SpamCop to point out the reporter's mistake, the IP address is taken off the blocklist (usually within 48 hours for spam; immediately for reporter error).
It may be that your call is the first time your ISP has heard that SpamCop has listed your IP address. Listings are made, in addition to member reporting, automatically from spamtraps (an eMail address that is not used, nor published anywhere, so only gets eMail if someone is sending spam!).
Your ISP can find out about SpamCop at http://www.spamcop.net/fom-serve/cache/76.html if they don't already know about SpamCop.
SpamCop deputies have access to the full evidence for a listing. Deputies can delist IP addresses which are listed in error.
Q: My ISP says it's not their fault. A: People in this forum will help with information to give your ISP
You will need to know your IP address for people to understand what has happened (it should be in the message you received telling you your mail was blocked).
It is also helpful to know the reasons why it was blocked. (To do this, go to http://www.spamcop.net/bl.shtml. Make a note of the reason for the listing. For example "Been reported as a source of spam about 30 times" "Been detected sending mail to spam traps" as this is important)
There are many people who will explain to you what has happened and what you can do.
If you are interested in finding out more about blocklists and exactly why your email was blocked, you may post
in the web forum SpamCop Blocking List Forum
or in the SpamCop NNTP newsgroup news://news.spamcop.net/spamcop.help with the above information.
Please remember that this block is not aimed at you personally. There are a limited number of IP addresses on the Internet, so you, and the spammer, may get a different one each time you log-on. Your Internet Service Provider is the only one who can investigate and take action to stop spam from coming from that IP address. In the meantime, the email service at the other end does not have to accept spam. If your email is coming from the same IP address, then the email service will not accept it either.
Revised 25 August 2010 - character-set issues yet again
Revised 18 April 2006 - updated List of DNSBLs link
Revised 17 Feb 2005 - Clarification of non-SMTP-reject e-mail generation
Revised 2 February 2005 Revised the time period of listing and added comment that there are two sections Miss Betsy
Revised 26 Jan 2005 - Wazoo added some of WB8TYW's input - more to come
Revised 18 Nov 2004 - Wazoo added DNSBL List URL
Revised 16 Nov 2004 - Wazoo - Ouch! newsgroup link fixed!
Revised 2 Sep 2004 - Wazoo
Revised August 7, 2004 - Miss Betsy, Wazoo, dbiel
Edited per Wazoo comments March 6, 2004
rev March 7
rev Mar 8 for format (agsteele)
Rev Mar11 with more links
Rev Mar 12 with new John link
rev 13 listized "Probable Causes"
rev 14 consolidated some links
rev 15 dbiel - worked on hyper links. They work fine in preview mode but when saved the code reverts to plain text.
Note: html is currently not permitted in pinned posts
No, problem is based on something else .....
Edit dbiel: It seems I was a bit too hasty, The problem is related to the permission level of the owner of this topic.
Rev not working link - MB
Contributors: Michaell, Mike Easter, Wazoo, Greenlady, John, JT, JeffG, WB8TYW
changed contact address per RW's suggestion - Miss Betsy
Link to archive regarding broken link: http://forum.spamcop.net/forums/index.php?showtopic=6221[/url]
Edited by Wazoo, 25 August 2010 - 05:07 PM.