How to prevent backscatter spam at server level
Configure Postfix to block spam before it enters the server
Sep. 10, 2019 - Willem L. Middelkoop
This month I had to deal with backscatter spam, affecting one of the mail servers I manage. As server engineer I make sure that servers don't send spam and that incoming email gets filtered. Despite all good efforts, this server kept being blacklisted for sending spam to iCloud, Office 365 and Google Gmail for Business (G Suite). Read along to find out how what caused this and how to fix this.
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