DNS Blacklist and mail proxy

HCL Domino Domino Forum
1

I have the following issue related to spam and DNS blacklist settings.

My domino server does not receive mail directly, but throgh a mail proxy hosted by my provider.

I enabled DNS blacklist filter, but it has no effect as domino server considers that mail stream is coming always from the mail proxy (that is not listed in any blacklist).

Unfortunately my provider does not perform a deep antispam control, so basically we receive tons of unsolicited emails.

Upon my complaints about that, my provider told me that “domino should be configured to look at the second line of the mail headers, so it can understand which is the actual server that is sending mail.”

Maybe I’m wrong, but I don’t think this is possible.

Is there someone that could clarify this, and possibly suggest me a solution?

TIA

Marco Zanovello

2

Subject: DNS Blacklist and mail proxy

You are right. It is not possible to interrogate the DNSBL status of any hosts in received headers during protocol handshake because they are in the message data (not yet transmitted) and not in any SMTP protocol field (HELO, MAIL, RCPT).

Your provider seems to be telling you to eat your spam and process it afterwards.

Plenty of tools will do this for you and I am sure others will offer suggestions. But none of these tools can prevent the loss of bandwidth, storage and processing power caused by having to accept every spam in full before deciding what to do with it.

Chris Linfoot