7

I've been receiving (a lot of) backscatter for ages. My hosting provider (I'm on a managed mail server) says there's not much we can do about it. I've read about BATV and looked at Spamcop's FAQ Under Construction on the topic. On SpamResource.com I've read the following that makes sense to me:

It might be useful to report backscatter as spam via your favorite spam-reporting service. It helps to collect stats on the problem, and helps to nudge sites to fix their backscatter-generating problems.

Would you agree that this is useful? If so, do you know any spam-reporting services where I could do this reporting?

6
  • 1
    While I may not like backscatter, by some standards they are considered legitimate bounce-backs even if they are responding to spam sources. I would suggest using SPF whitelist approach to help the backscatter-creators to know it is spam they are responding to. – 700 Software Nov 2 '16 at 18:30
  • 1
    You cannot stop all Spam by any means. Stopping Bounce-backs to spam is easier because you are dealing with legitimate mailservers in many cases, but there are so many mailservers in the world that chances are you cannot stop it completely. I know that some ISPs can take action, but IIRC, some ISPs simply will not respond to reports you send in. I know this doesn't really answer your question, but it is related and perhaps helpful. – 700 Software Nov 2 '16 at 18:32
  • 1
    My thinking was that having a dedicated backscatter reporting service, would allow it to focus on recording different data (e.g. some information about the original sender), so practically different from reporting it as spam. Still, I'm not sure how much useful information would be possible to extract from the bounce mails, given that they vary so much. Was hoping that other people would have better ideas that I just missed or underestimated in my search. – mapto Nov 2 '16 at 22:03
  • 1
    Most bounce backs I see include the original (spam) headers and would provide much useful information. – 700 Software Nov 3 '16 at 12:40
  • 1
    How to submit spam, and false-positive spam samples to SophosLabs - Sophos Community - community.sophos.com/kb/en-us/23113#macmail – Mark May 15 '17 at 6:11
2

First a few thoughts about backscatter: you should differentiate between real DSN (delivery status notifications) and backscatter (where there was no original email from you to reply to). You should not fight against DSN since it's integral part of the email system, and - despite what some people say - useful most of the time.

Stopping fake bounces to emails you've never sent is not hard, and probably BATV is the most logical way to go. You must be aware of the restrictions though: you have to use your specific BATV mail relay for both inbound and outbound mail, since it is imperative that all your outbound get its keyed sender and all your inbound gets verified. If you neglect this you may get your email bounced by Sender Address Verifying (SAV) servers, or the replies to you may get bounced back by your inbound server.

Using DKIM and SPF may also help to prevent the bounces with less efficiency since it require the recipient to check the signature, but in case you're using a central relay you may implement that easily as well (and for a bonus you make it harder your mail to get spoofed).

As for reporting bounces I see no real benefit in that, even less than reporting spam individually. Most bounces contain little to no original headers, so you cannot report on the original spammer, and these mailservers have often not so professional admins with default configurations and in my experience litte room to change. The time you'd spend on reporting would be mostly wasted.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.