Problem to send eMail

[Liox]

On some IP's, I have problems to send eMails out.
In the mail.info I just find:
relaylock: /var/qmail/bin/relaylock: mail from 84.134.101.139:58851 (p5486658b.dip.t-dialin.net)

In another case I can send out mails:

Feb 21 11:35:24 h1204277 relaylock: /var/qmail/bin/relaylock: mail from 87.171.120.11:63100 (p57ab780b.dip.t-dialin.net)
Feb 21 11:35:24 h1204277 smtp_auth: SMTP connect from unknown@p57ab780b.dip.t-dialin.net [87.171.120.11]
Feb 21 11:35:24 h1204277 smtp_auth: smtp_auth: SMTP user micha@XXXXXX.de : /var/qmail/mailnames/XXXXXXX.de/micha logged in from unknown@p57ab780b.dip.t-dialin.net [87.171.120.11]
Feb 21 11:35:25 h1204277 qmail-queue[26770]: mail: all addreses are uncheckable - need to skip scanning (by deny mode)
Feb 21 11:35:25 h1204277 qmail-queue[26770]: scan: the message(drweb.tmp.AQwwXc) sent by micha@hXXXXXXX.de to liox@XXXXXX.nu should be passed without checks, because contains uncheckable addresses
Feb 21 11:35:25 h1204277 qmail: 1172054125.190638 new msg 17581008
Feb 21 11:35:25 h1204277 qmail: 1172054125.190702 info msg 17581008: bytes 1380 from <micha@XXXXXXXX.de> qp 26771 uid 2020
Feb 21 11:35:25 h1204277 qmail: 1172054125.206899 starting delivery 3: msg 17581008 to remote liox@XXXXXXX.nu
Feb 21 11:35:25 h1204277 qmail: 1172054125.206978 status: local 0/10 remote 1/20
Feb 21 11:35:26 h1204277 qmail: 1172054126.754328 delivery 3: success: 84.184.245.211_accepted_message./Remote_host_said:_250_Ok:_queued_as_D73AF87C1B/

Plesk Settings: Authorization over SMTP,
SPF-Spam off, MAPS-Spam off

So, what is wrong? Why I can send Mail from one IP and not from another?

Thanks in advance

By Michael

 

[Liox]

has no one a glue why this happens? Why I don't get even a authentication failed or something?

But may I have another problem too:
I'll tried:
telnet XXXXXXXXXXX.de 25
Trying XXXXXXXXXXX...
Connected to XXXXXXXXXXX.de.
Escape character is '^]'.
220 XXXXXXXXXXXXXXX.de ESMTP
MAIL FROM liox@domain.com
250 ok
RCPT TO micha@domain.com
250 ok
data
354 go ahead
subject=test
content
.
250 ok 1172087149 qp 32564


is this a open relay?
should there not a message like
554 <micha.domain.com>: Relay access denied