postfix mit saslauthd und plain-authentifizierung

[m@rio]

Ich glaub da könnte das Problem liegen.

smtpd_recipient_restrictions = reject_invalid_hostname, reject_non_fqdn_hostname, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, permit_mynetworks, reject_unauth_destination, reject_rbl_client zombie.dnsbl.sorbs.net, reject_rbl_client relays.ordb.org, reject_rbl_client opm.blitzed.org, reject_rbl_client list.dsbl.org, reject_rbl_client sbl.spamhaus.org, permit

Da sollte statt permit wahrscheinlich permit_sasl_authenticated stehen.

Probiers zum testen eventuell mal so
smtpd_recipient_restrictions = permit_mynetworks permit_sasl_authenticated reject_unauth_destination