On Tue, Aug 23, 2016 at 05:57:37PM +0200, Sam wrote: > Hello, > > Sometime when we receive a spam or virus that is detected as it, mailer > daemon send a reply to the sender to inform that the message is a spam or > content viruses.
You probably shouldn't do this. The vast majority of spam / virus emails are sent from compromised machines / botnets, use fake return paths, and either don't monitor replies, or just use replies to verify that the email address is valid and send more spam to it. Or worse, it can turn your server into a spamming machine if the return addresses are set to other people's email addresses. There are several valid ways of handling spam, depending on how your mail architecture works. One is to reject incoming spam messages at the receiving mailserver. The downside is that this leaks information to the spammers about what spam methods actually get through or not. Another method is to accept all incoming messages, then sort / quarantine / blackhole any spam. The downside is that this makes your server seem more accepting, which may attract more spam. I personally take the second approach, though which is better will definitely depend on how your specific system works. If you're really dead set on having some sort of auto reply, at the very least make it only reply to senders that have historically sent good messages (e.g. some sort of whitelist). --Sean
