I find I can no longer send emails to two of my email correspondents, though all the others are operating normally. When I try, I get a message "Undelivered Mail Returned to Sender", saying that my message has been intercepted by an organisation named "SpamCop", which treats it as spam - which it isn't! I thought at first my friends had subscribed to a spam filter that was too aggressive, but they haven't! So who or what is SpamCop, and how can I get my emails through? Any ideas, anyone?

Although SpamCop also has a free reporting service, if your friends mail is being *intercepted* by SpamCop, they are indeed subscribed.  It could be that they don't realize it because they haven't subscribed manually by themselves, but are using a filter or an email service which itself uses SpamCop.  The most likely reason for your mail being blocked is that your ISP or email service provider is used by spammers, and the whole service is therefore blacklisted.

I don't know exactly how to solve the problem, but a temporary workaround might be to mail your friends from a free email service such as GMail, which will not have your ISP listed in the standard email headers.  For a more permanent solution, you might try contacting SpamCop.  Their contact page is at http://www.spamcop.net/fom-serve/cache/401.html .  Your ISP also may have some ideas.

Are you sure that the message says that the mail has been blocked *by* SpamCop, and not just that it was blocked because it appears on a SpamCop list?

Good luck.
C.  

Many thanks for the information, which I'll try to use to solve the problem and report back if I get anywhere with it. To clarify things, the messages I received are slightly different between the two intended recipients. For one of them, I got:

This is the SMTP Server program at host me.freeserve.com.

I'm sorry to have to inform you that your message could not be
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The SMTP Server program

<[My friend's email address]>: host
    relay1.themail.hotchilli.net[62.89.140.201] said: 554 Service unavailable;
    Client host [193.252.22.156] blocked using bl.spamcop.net; Blocked - see
    http://www.spamcop.net/bl.shtml?193.252.22.156 - see http://bl.spamcop.net
    (in reply to RCPT TO command)

and the other:

This is the SMTP Server program at host me.freeserve.com.

I'm sorry to have to inform you that your message could not be
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

The SMTP Server program

<[My friend's email address]>: host mta5.rdslink.ro[193.231.236.78] said: 553 Blocked - see
    http://www.spamcop.net/bl.shtml?193.252.22.156 (in reply to RCPT TO
    command)

In each case, my original message came back as an attachment, plus another attachment as a .dat file, one of which was:

Reporting-MTA: dns; me.freeserve.com
X-SMTP-Server-Queue-ID: A16138000088
X-SMTP-Server-Sender: rfc822; [My email address]
Arrival-Date: Thu, 14 Sep 2006 09:35:12 +0200 (CEST)
Content-Type: text/plain

Final-Recipient: rfc822; [My friend's email address]
Action: failed
Status: 5.0.0
Diagnostic-Code: X-SMTP-Server; host mta5.rdslink.ro[193.231.236.78] said: 553
    Blocked - see http://www.spamcop.net/bl.shtml?193.252.22.156 (in reply to
    RCPT TO command)

I don't know if any of that helps you to understand my problem, or just adds confusion! I'm not too sure what is meant by <postmaster> - is that meant to be my ISP or the recpient's?

Thanks again.

   The solution that Cassandra suggested is probably the only thing you can do.  The only other solutions are to buy your own unique IP number (see below) and send through it or ask your friends that are not getting your emails to ask their providers to remove the block.
   Many email providers use SpamCop to control their spam (it seems like just about all Netherlands email providers now use it).
   They usually do this without your permission or knowledge.  I contacted one of my email providers a couple of years ago and asked them to remove SpamCop from blocking my emails.  They told me that they actually used four such lists to block spam.  They removed them all.  It meant that I received more spam (the spam lists never blocked all or most of the spam), but at least I receive all of my emails.  I still get my emails to other people blocked.
   SpamCop blocks IP numbers (that is the 193.252.22.156 number) and not email addresses.  Unless you are paying your email provider to have your own unique IP number, you share IP numbers with everyone serviced by your email provider.  If one of them are blocked, you get blocked.
   I have found SpamCop to be very irresponsible when it comes to blocking.  I somehow got a few email addresses on our newsletter list that SpamCop monitors.  When I send my newsletter to those email addresses, SpamCop puts me on their list.  I tried to get them to tell me which email addresses they were so that I could remove them from our list, but they refuse to tell me and they refuse to keep me off their list even though they agreed that I was not sending out spam.

Spamcop is a spam filtering service to which I am subscribed. As a result I get about ONE spam a month on average. But some genuine messages may get blocked too, which seems to your case.

If you follow the links you will find a lot of useful info and you don't have to subscribe to deal with your problem

I am not sure , but I am subscribed to mailwasher pro which has a feature related to Spam cop ; it is to my oipinion impossible that Spam cop blocks anybody e-amil without beeing asked for ; the only possibility is that one of your friends , dooes not know how to use mailwasher or made a mistake using it, if that's the case , and that's very likely , tell your friend , calling him by phone or using usal mail that he must clean his blacklist in mailwasher ; he should always check mailwasher at opening instead of letting it wash his mail automatically . Best regards OLIVIER GEBUHRER

   TCHAPAIEV, many email providers use SpamCop without their customers knowing about it.  If your email provider uses SpamCop, you will not get emails from people on SpamCop's list and that will be done without your permission.  I know this to be true.

   I just did a test to see how much spam SpamCop blocks.  Anyone with MailWasher can do this.  I waited an hour and a half then I ran MailWasher.  I had 15 emails.  Two of those emails were not spam.  SpamCop listed one of the valid emails as spam and only 5 of the 13 spam as spam.
   So in my test, SpamCop listed half of the valid emails as spam and less than half of the spam as spam.

My friends deny all knowledge of having subscribed to SpamCop, so I contacted my ISP and asked for advice. I was pointed to this link:

http://help.orange.co.uk/sessionBegin.do?solutionId=kb6265

As you can see, they claim to try very hard to remove their mail servers from blacklists but I am still at the mercy of SpamCop and others. I did try contacting one of my friends via Lycos Web Mail, but with no success, which suggests that it is my IP number that is being blocked, rather than a mail server, but it’s hard to be sure. I have now sent details of my friends’ ISPs to my ISP, in the hope that they can follow up whatever line they see fit, but I am waiting to hear any more from them. I will post details of any success I may have in the future, but don’t hold your breath! Meanwhile, thanks to everyone who has tried to help.

I have now had a reply from my ISP. Unless and until they can resolve anything, I feel I have reached the end of the road on this one. It reads (in part):

It appears that your email has been blocked by an anti-spam blacklist.

We are in contact with several well-recognised blacklisting
organisations, such as http://www.spamcop.net and http://www.spamhaus.org, helping us
to make sure that their subscribers do not block our mail servers.  It's
not always possible for us to keep in contact with all of these
organisations, especially the smaller providers such as http://www.spews.org,
who do not provide any contact details at all. Unfortunately there's
nothing we can do if an organisation chooses to subscribe to this
blacklist.

We are continually striving to improve this situation wherever possible
and apologise for any inconvenience.