Qmail ta entregando ALGUMAS mensagens outras não

Explicando meu problema.

Um servidor envia as faturas por email via sendmail para o meu qmail que faz a entrega das mensagens pra fora.
O que acontece.
No log no sendmail (maillog) aparece o email saindo.

[email protected] é o DESTINATÁRIO
[email protected] - REMETENTE


[root@servidor log]# tail -f maillog | grep -i [email protected]
Sep 19 11:56:31 servidor sendmail[29051]: l8JEuQW29049: [email protected] ctladdr=mariana (641/642), delay=00:00:05, xdelay=00:00:05, mailer=relay, pri=63620, relay=smtp.DOMINIO_QMAIL.com.br. [192.168.0.2], dsn=2.0.0, stat=Sent (ok 1190213008 qp 26672)

Sep 19 11:56:31 servidor sendmail[29046]: l8JEuQ229044: [email protected], ctladdr=mariana (641/642), delay=00:00:05, xdelay=00:00:05, mailer=relay, pri=49090, relay=smtp.DOMINIO_QMAIL.com.br. [192.168.0.2], dsn=2.0.0, stat=Sent (ok 1190213008 qp 26674)



2007-09-19 11:43:30.947270500 delivery 7057: failure: Connected_to_64.97.153.5_but_sender_was_rejected./Remote_host_said:_553_<[email protected]>_unable_to_verify_address/
2007-09-19 11:43:30.947437500 status: local 1/10 remote 8/60
2007-09-19 11:43:30.947516500 delivery 7058: failure: Connected_to_64.97.153.5_but_sender_was_rejected./Remote_host_said:_553_<[email protected]>_unable_to_verify_address/
2007-09-19 11:43:30.947625500 status: local 1/10 remote 7/60
2007-09-19 11:43:30.947724500 end msg 34375888

2007-09-19 11:43:32.160393500 status: local 1/10 remote 6/60
2007-09-19 11:43:32.324571500 bounce msg 34375852 qp 26812
2007-09-19 11:43:32.324658500 end msg 34375852
2007-09-19 11:43:32.324888500 delivery 7064: failure: Connected_to_64.97.153.5_but_sender_was_rejected./Remote_host_said:_553_<[email protected]>_unable_to_verify_address/
2007-09-19 11:43:32.325058500 status: local 1/10 remote 5/60
2007-09-19 11:43:32.325219500 new msg 34375872
2007-09-19 11:43:32.325303500 info msg 34375872: bytes 86730 from <[email protected]> qp 26791 uid 89
2007-09-19 11:43:32.671848500 bounce msg 34375760 qp 26831



Alguém poderia mi dar uma ajuda nisso ?