Tag Archives: smtpd_client_restrictions

Stop spammers at the gate: Don’t blindly trust SASL authenticated connections

Recently a user’s email password was cracked. Not long after, she started receiving hundreds of bounce messages. My first thought was that these messages were back scatter, produced when spammers insert any random sending server address. So bounce messages are misdirected to that unsuspecting server. But the messages kept coming. So I started thinking she … Continue reading →

Posted in: System Administration