littlekorea writes "MessageLabs claims to have discovered that the systems of one of its customers were hacked by spammers after an entire block of MessageLabs IP addresses was blocked by antispam service SORBS. Customers of the managed email service had problems with outbound mail last week after MessageLabs' IP addresses were included in SORBS' block list. The Symantec-owned service provider has assured customers it has systems in place to prevent such incidents from happening again."
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