SpamAssassin RBL details

[Jan-Peter Koopmann]

Hi David,
 
> We have an SMTP proxy running in front of MailScanner on our 
> mail server, I am wanting to turn RBL checking on, but seeing 
> as all connections are seen as arriving from 127.0.0.1 by 
> MailScanner I'm not sure if the RBL's will work.

That does not make sense. MailScanner is not working on IP based but
file based. The MTA is receiving the mail via IP and is recording from
which IP it receives the mail. Are you saying this is 127.0.0.1 so all
e-mail you receive is sent by your machine itself? The only other
possibilities I know in which this would happen is using fetchmail to
retrieve POP3/IMAP mails and send it to the MTA or using stunnel (for
using SMTP SSL AUTH with some braindead MS MUAs).

> Can someone explain to me how the RBL checks are performed?  
> Does it look at all the relaying IP's in the headers or does 
> it use the connecting IP and therefore only see 127.0.0.1?

AFAIK it i inspecting all "Received" header lines.

Regards,
  JP