May 27 12:57:30 ashley postfix/smtpd[11258]: connect from ashley.tuxblogger.nl[84.245.7.46]
May 27 12:57:31 ashley postfix/smtpd[11258]: NOQUEUE: reject: RCPT from ashley.tuxblogger.nl[84.245.7.46]: 554 5.7.1 <ashley.tuxblogger.nl[84.245.7.46]>: Client host rejected: Access denied; from=<jelle@tuxblogger.nl> to=<jelle@tuxblogger.nl> proto=ESMTP helo=<[192.168.1.78]>
May 27 12:57:46 ashley postfix/smtpd[11258]: lost connection after RCPT from ashley.tuxblogger.nl[84.245.7.46]
May 27 12:57:46 ashley postfix/smtpd[11258]: disconnect from ashley.tuxblogger.nl[84.245.7.46]

(related settings)

postconf -e 'relayhost = smtp.tweakdsl.nl'
postconf -e 'mynetworks_style = host'
postconf -e 'smtpd_client_restrictions = permit_mynetworks, reject'
postconf -e 'smtpd_helo_restrictions = reject_unknown_helo_hostname'
postconf -e 'smtpd_sender_restrictions = reject_unknown_sender_domain'
postconf -e 'smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination'
postconf -e 'smtpd_data_restrictions = reject_unauth_pipelining'
postconf -e 'alias_maps = hash:/etc/aliases'

postfix reload