Thanks Thomas & Dilbert,

The chain is:

Internet -> Mercury -> pop3 connector -> Exchange 

I've realized what the problem was.

When I moved spam to spambucket@mydomain, Mercury was putting that mail into my Domain mailbox with

X-Envelope-To: spambucket@mydomain

To: OriginalRecepient@mydomain 

The Pop3 connector I'm using, by default was reading both these headers and sending a copy to both recipients. Fortunately, I can specify which headers get read, and ask it to read X-Envelope-To only.

 Regards,

Richard 

I'm trying to get incoming spam moved to another user. To this end, I have SpamHalter adding a subject prefix of [SPAM], and then I have a global filtering rule that on finding [SPAM] in the subject, moves the message to another user called spambucket@mydomain.

The problem I have is that if spam arrives for usera@mydomain, then spambucket is given a copy of that mail, but a copy also arrives for usera. I don't want usera to get a copy at all.

Could anyone tell me what I'm doing wrong here? The domain 'mydomain' is a Domain Mailbox, from which mails are being collected by a pop3  connector and then sent on to an Exchange server. Could it be at this step where the duplication is occuring?

Thanks,

Richard

Not sure what you are doing by I simply use a MOVE filter to make this happen with either Spamhalter or POPFileD.  I use the headers added by these programs rather than the subject line though.

[quote user="rhayward"]

The domain 'mydomain' is a Domain Mailbox, from which mails are being collected by a pop3  connector and then sent on to an Exchange server.

[/quote]

Where in this chain is mercury?