Here are brief but complete instructions to stop your Barracuda from sending backscatter, or outscatter — bounce notifications to people that should not get them. Out of the box the Barracuda sends a great many of these. There is no need for it. People get them and have no idea why. You know your users have called you, confused about non-delivery reports, virus blocking reports on messages they never sent....don't do it to others.
First we start off with virus filtering. The 'froms' are all forged, you know that. So stop sending notifications that you rejected the virus to people that have nothing to do with sending it. On the ' BASIC ' main tab hit ' Virus Checking '. Set 'Notify Sender of Virus Interception' select 'NO'. Do you want to confuse your users and cause them to call you? Of course not, so also set 'Notify Intended Recipient of Virus Interception' to 'NO'. Save Changes .
Next we fix the rejection notices from the filter. If you set it up right, your score for blocking on the filter is set high. So you know it is spam. And you also know the 'from' is forged, or the spammer does not care. So do not send a bounce notice to a forged address. On the main ' BASIC ' tab hit 'Spam Scoring'. At the bottom, set 'Send Bounce' to 'NO'. Save Changes .
The last one is a bit different. It is attachment blocking. Do not confuse that with virus checking. Barracuda first checks for Virus, then attachment blocking. But there is a Catch-22 in their set up. If you get an exe that has a virus it will trigger on that first and block it. But it still continues and checks the attachment rules. And if the attachment type is listed it will trigger on this also. So the exe with a virus will also trigger the attachment blocking and send a bounce, if you have it turned on. So on the BLOCK/ACCEPT main tab, set 'Notify intended receiver ..' and 'Notify sender ..' to 'NO'. Save Changes . We only block attachments that have no business on our email server, so this causes no problem for us.
