Anonymous

Logs:
Apr 28 08:36:00 backup postfix/pickup[12743]: 7B13D9A067: uid=1000 from=<car>
Apr 28 08:36:00 backup postfix/cleanup[12815]: 7B13D9A067: message-id=<20110428133600.GA12801@austin.bio-west.com>
Apr 28 08:36:00 backup postfix/qmgr[12744]: 7B13D9A067: from=<car@austin.bio-west.com>, size=435, nrcpt=1 (queue active)
Apr 28 08:36:00 backup postfix/smtp[12817]: 7B13D9A067: to=<rock@peppa.com>, relay=smtp.sbcglobal.yahoo.com[68.142.198.11]:587, delay=0.27, delays=0.01/0.01/0.22/0.04, dsn=5.0.0, status=bounced (host smtp.sbcglobal.yahoo.com[68.142.198.11] said: 553 From address not verified - see http://help.yahoo.com/l/us/yahoo/mail/original/manage/sendfrom-07.html (in reply to MAIL FROM command))
Apr 28 08:36:00 backup postfix/cleanup[12815]: CFBE69A06B: message-id=<20110428133600.CFBE69A06B@austin.bio-west.com>
Apr 28 08:36:00 backup postfix/bounce[12818]: 7B13D9A067: sender non-delivery notification: CFBE69A06B
Apr 28 08:36:00 backup postfix/qmgr[12744]: CFBE69A06B: from=<>, size=2515, nrcpt=1 (queue active)
Apr 28 08:36:00 backup postfix/qmgr[12744]: 7B13D9A067: removed
Apr 28 08:36:01 backup postfix/smtp[12817]: CFBE69A06B: to=<car@austin.bio-west.com>, relay=smtp.sbcglobal.yahoo.com[68.142.198.11]:587, delay=0.16, delays=0/0/0.13/0.02, dsn=5.0.0, status=bounced (host smtp.sbcglobal.yahoo.com[68.142.198.11] said: 501 Syntax error in arguments (in reply to MAIL FROM command))
Apr 28 08:36:01 backup postfix/qmgr[12744]: CFBE69A06B: removed

postconf -n

alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
config_directory = /etc/postfix
inet_interfaces = loopback-only
inet_protocols = ipv4
mailbox_command = 
mailbox_size_limit = 0
mydestination = localhost
myhostname = austin.bio-west.com
mynetworks = 127.0.0.0/8 10.1.1.0/24
myorigin = /etc/mailname
readme_directory = no
recipient_delimiter = +
relayhost = [smtp.sbcglobal.yahoo.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache