These commands are required and do run, but they echo their argument back to the user rather than expanding the argument to indicate whether it is valid or invalid. Turns on SMTP security logging. Any invalid user given to the RCPT commands is also logged. The log message is sent to syslogd as a mail.warning message. AIX is vulnerable to this problem.
Fixes are in process.
The APAR numbers for the fixes are given below. APAR - IX59742. AIX Version 3 is vulnerable to this problem. AIX Version 4 does not contain this vulnerability. With this vulnerability a user can gain unauthorized access to another user's mail.