Postfix rejecting email

[inertia]

I have tested my newly created email with a hotmail account and I can receive the mail so I know it is working.

However, when I send from my work account , the work account receives a rejection email.

Action: failed
Status: 5.1.1
Remote-MTA: DNS; mail.xxx.xx
Diagnostic-Code: SMTP; 550 authentication required
Last-Attempt-Date: Wed, 1 Aug 2012 15:38:13 +0200

I have tried playing around with the settings in main.cf and removing the reject* lines to no avail.

Code:

smtpd_helo_required          = yes

smtpd_helo_restrictions      = permit_mynetworks,
                               permit_sasl_authenticated,
                               reject_invalid_helo_hostname,
                               reject_non_fqdn_helo_hostname

smtpd_sender_restrictions    =  permit_mynetworks,
                               permit_sasl_authenticated,
                                reject_non_fqdn_sender,
                                reject_unknown_sender_domain

smtpd_recipient_restrictions = reject_non_fqdn_recipient,
                               reject_unknown_recipient_domain,
                               permit_mynetworks,
                               permit_sasl_authenticated,
                               reject_unauth_destination,
                               reject_unlisted_recipient,
                               check_policy_service inet:127.0.0.1:12525,
                               check_policy_service inet:127.0.0.1:10023,
                               permit

smtpd_data_restrictions      = reject_multi_recipient_bounce,
                               reject_unauth_pipelining