Public bug reported: The Mailman.Mailbox.Mailbox.AppendMessage method has an invalid seek to position the file to the end of the mailbox. It contains . # Seek to the last char of the mailbox . self.fp.seek(1, 2) This actually should be self.fp.seek(0, 2). There is no actual ill effect in Mailman itself from this bug as Mailman always opens mailbox files to be written to in 'a+' mode and seeks before writes are ignored for files opened in append mode, but if someone creates a process which opens a file in 'w+' mode and then uses the Mailman.Mailbox.Mailbox.AppendMessage method to add messages to it, each added message's UnixFrom is preceded by a null byte. ** Affects: mailman Importance: Low Assignee: Mark Sapiro (msapiro) Status: Confirmed -- You received this bug notification because you are a member of Mailman Coders, which is subscribed to GNU Mailman. https://bugs.launchpad.net/bugs/901957 Title: Mailman.Mailbox.Mailbox.AppendMessage method can add null bytes to mailbox. To manage notifications about this bug go to: https://bugs.launchpad.net/mailman/+bug/901957/+subscriptions