Exim Issue + Retry And Retry.lockfile

Exim on my dedicated have been a very strage comportment. If I try send email for some domains I receive errors as:

========================
root@server01 [/var/spool/exim/db]# mail -v xx@terra.com.br
Subject: lol10
.
Cc:
Null message body; hope that's ok
LOG: MAIN
<= root@server01.xxxx.com U=root P=local S=377
root@server01 [/var/spool/exim/db]# delivering 1K3Ptz-000110-L8
Connecting to mx.terra.com [200.154.55.2]:25 ... connected
SMTP<< 450 Client host rejected: cannot find your hostname, [xx.228.179.xx]
SMTP>> QUIT
LOG: MAIN
SMTP error from remote mail server after initial connection: host mx.terra.com.br [200.154.55.2]: 450 Client host rejected: cannot find your hostname, [xx.228.179.xx]
LOG: MAIN
== xx@terra.com R=lookuphost T=remote_smtp defer (0): SMTP error from remote mail server after initial connection: host mx.terra.com.br [200.154.55.2]: 450 Client host rejected: cannot find your hostname, [xx.228.179.xx]
========================

But My server have RDNS and PTR configured correct.

So If I try again I receive other kind of error as:

========================
root@server01 [/var/spool/exim/db]# mail -v xx@terra.com.br
Subject: ggg
.
Cc:
Null message body; hope that's ok
LOG: MAIN
<= root@server01.xx.com U=root P=local S=375
root@server01 [/var/spool/exim/db]# delivering 1K3Pyt-00014j-3C
LOG: retry_defer MAIN
== xx@terra.com.br R=lookuphost T=remote_smtp defer (-53): retry time not reached for any host
=============================

But If I delete file /var/spool/exim/db/retry and /var/spool/exim/db/retry.lockfile before sending i can send message without any problem. So If I try again some minutes later the problem come back.