Yes, I followed the tutorial at docs.iredmail.org/relayhost.html but not sure whether I should be using smtp or smtpd in those commands. (smtp_sasl_password_maps = hash:/etc/postfix/sasl_password) it would seem it should be smtpd_sasl etc as all the other lines in the main.cf are using smtpd_sasl
Here is the log from maillog:
Jul 30 18:32:59 mail postfix/postfix-script[31282]: starting the Postfix mail system
Jul 30 18:32:59 mail postfix/master[31284]: daemon started -- version 3.3.0, configuration /etc/postfix
Jul 30 18:33:23 mail postfix/submission/smtpd[31309]: connect from host225-131-dynamic.246-95-r.retail.telecomitalia.it[95.246.131.225]
Jul 30 18:33:25 mail postfix/submission/smtpd[31309]: Anonymous TLS connection established from host225-131-dynamic.246-95-r.retail.telecomitalia.it[95.246.131.225]: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)
Jul 30 18:34:02 mail postfix/submission/smtpd[31309]: 7432B18179A: client=host225-131-dynamic.246-95-r.retail.telecomitalia.it[95.246.131.225], sasl_method=PLAIN, sasl_username=name@example.co.nz
Jul 30 18:34:03 mail postfix/cleanup[31353]: 7432B18179A: message-id=<ED2D0FFC-CF36-4947-86E9-CA72BB3BD1A5@example.co.nz>
Jul 30 18:34:03 mail postfix/qmgr[31286]: 7432B18179A: from=<name@example.co.nz>, size=728, nrcpt=1 (queue active)
Jul 30 18:34:04 mail postfix/10025/smtpd[31362]: connect from mail.example.co.nz[127.0.0.1]
Jul 30 18:34:04 mail postfix/10025/smtpd[31362]: 452B818179C: client=mail.example.co.nz[127.0.0.1]
Jul 30 18:34:04 mail postfix/cleanup[31353]: 452B818179C: message-id=<ED2D0FFC-CF36-4947-86E9-CA72BB3BD1A5@example.co.nz>
Jul 30 18:34:04 mail postfix/10025/smtpd[31362]: disconnect from mail.example.co.nz[127.0.0.1] ehlo=1 mail=1 rcpt=1 data=1 quit=1 commands=5
Jul 30 18:34:04 mail postfix/qmgr[31286]: 452B818179C: from=<name@example.co.nz>, size=1236, nrcpt=1 (queue active)
Jul 30 18:34:04 mail amavis[16661]: (16661-20) Passed CLEAN {RelayedInbound}, ORIGINATING [95.246.131.225]:54690 [95.246.131.225] <name@example.co.nz> -> <example@icloud.com>, Queue-ID: 7432B18179A, Message-ID: <ED2D0FFC-CF36-4947-86E9-CA72BB3BD1A5@example.co.nz>, mail_id: qtpc_sJbb7Fv, Hits: -1, size: 728, queued_as: 452B818179C, 642 ms, Tests: [ALL_TRUSTED=-1]
Jul 30 18:34:04 mail postfix/amavis/smtp[31359]: 7432B18179A: to=<example@icloud.com>, relay=127.0.0.1[127.0.0.1]:10026, delay=2.5, delays=1.8/0.03/0.01/0.65, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as 452B818179C)
Jul 30 18:34:04 mail postfix/qmgr[31286]: 7432B18179A: removed
Jul 30 18:34:06 mail postfix/smtp[31363]: Trusted TLS connection established to smtp.smxemail.com[203.84.134.6]:587: TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)
Jul 30 18:34:06 mail postfix/smtp[31363]: 452B818179C: to=<example@icloud.com>, relay=smtp.smxemail.com[203.84.134.6]:587, delay=2.2, delays=0.03/0.05/2.2/0, dsn=5.7.1, status=bounced (host smtp.smxemail.com[203.84.134.6] said: 550 5.7.1 Authentication is required to use this service (in reply to MAIL FROM command))
Jul 30 18:34:06 mail postfix/cleanup[31353]: 8795618179E: message-id=<20180730063406.8795618179E@mail.example.co.nz>
Jul 30 18:34:06 mail postfix/bounce[31367]: 452B818179C: sender non-delivery notification: 8795618179E
Jul 30 18:34:06 mail postfix/qmgr[31286]: 8795618179E: from=<>, size=3366, nrcpt=1 (queue active)
Jul 30 18:34:06 mail postfix/qmgr[31286]: 452B818179C: removed
Jul 30 18:34:06 mail postfix/pipe[31368]: 8795618179E: to=<name@example.co.nz>, relay=dovecot, delay=0.08, delays=0/0.02/0/0.05, dsn=2.0.0, status=sent (delivered via dovecot service (doveconf: Warning: SSLv2 not supported by OpenSSL. Please consider removing it from ssl_protocols.))
Jul 30 18:34:06 mail postfix/qmgr[31286]: 8795618179E: removed