qmail is a mail transfer agent that runs on Unix. It was written by Daniel J. Bernstein as a more secure replacement for the popular Sendmail program.The author offered a US$500 reward for the first person to publish a verifiable security hole in the latest version of the software. As of 2006, these rewards still stand, though Georgi Guninski claims a bug is remotely exploitable. Bernstein himself denies that Guninski's claim meets his qualifications.
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