Why do spammers generate backscatter

Contents Exit focus mode. Important The improved Microsoft Defender portal is now available. Tip The Backscatterer. Is this page helpful? Yes No. Any additional feedback? Consider using the following methods to reject garbage at the Receiver: Configure SpamProfiler to reject spam at connection time. Use an effective Reputation Service like Spamhaus. Reject all traffic to invalid addresses.

This is especially crucial if there is a chance your internal mail server will reject invalid addresses when SEG attempts to pass it on. This causes SEG to become an instant backscatter source. While Challenge-Response may help clear up your own inbox, it generates unwanted traffic for everyone else. Use Out-of-Office notifications to the outside world as sparingly as possible. Here's how Imagine that a spammer used your address for the "from" header of his spam.

I suppose I should say "his or her" spam, but it seems like women are too smart to become spammers. Now imagine that the recipient is out of the office, and automatically replies to the spam message. In that case, you're going to get the out-of-office message in your inbox.

It comes out of the blue, from someone you don't know. That's confusing and irritating, but it doesn't happen very often these days, because most people filter spam before their email server, so their out-of-office robot doesn't usually get to see the spam message. Also because, well, people aren't usually on vacation.

However, if the spammer forges your email address to be the 'sender' of millions of spam messages, you're likely to end up with a messy inbox. It's not just out-of-office messages that you'd see. In fact, any sort of reply can cause backscatter. Here are three more examples Sadly, some people persist in replying to spam. None of the spam messages pass through FSU's servers, so there isn't any way that we can block the spam from going out. Also, since the backscatter messages are generated by servers all over the world, most of which are legitimate and not spammers, we can't block those either.

Can I use mail filters to filter the bounces? Many bounces will contain strings that can be recognized by a mail filter. You won't be able to filter all the bounce messages out, but you may be able to reduce the number you see. However, if you choose to do this, you may run the risk of filtering out legitimate bounce messages for emails that you DID send, but were not delivered. Why is it so hard to filter all the bounces? Every mail system seems to invent its own way of reporting undeliverable mail.

There is absolutely no standard form for the return messages and they can contain any address in the 'From:' line. Challenge-response systems are even worse than regular MTA's, which are at least slightly consistent. These tests may or may not work for you. They will probably reduce the number of bounces you see, but they will not catch all of them. These tests could delete important mail. Use with care.