[Exim] How can exim4 get a 554 error but telnet 25 works?

Here is the error.

2004-04-22 08:44:36 1BGdWa-00066q-FV ** konrad.roeingh@???
<Konrad.Roeingh@???> R=dnslookup T=remote_smtp: SMTP error from
remote mailer after end of data: host mail1.sms-demag.de [62.159.28.1]:
554 Error writing message to safe storage; message could not be stored
to disk
2004-04-22 08:44:36 1BGdZE-0006Bs-VR <= <> R=1BGdWa-00066q-FV
U=Debian-exim P=local S=2527
2004-04-22 08:44:36 1BGdWa-00066q-FV Completed

Despite saying "Completed" this email is not received. I'm using small
test emails containing a few lines of ascii.

Supposedly, they can receive email from others. I'm a bit green on such
matters but as I understand it this error comes from their server. What
does not make sense is that I can telnet an email using the same IP.

Debian unstable
Exim 4. Version: 4.32-2
MailScanner Version: 4.29.7-2
There is no local mail delivered on my server.

This problem has persisted over two upgrades.

Any enlightenment or pointers to relevant reading would be appreciated.

Below is the telnet session.


Thanks

Scott Hancock
Morgan



pebbles:~# telnet 62.159.28.1 25
Trying 62.159.28.1...
Connected to 62.159.28.1.
Escape character is '^]'.
220 mail1.sms-demag.de ESMTP Service (Lotus Domino Release 5.0.12) ready
at Thu, 29 Apr 2004 14:50:58 +0200
ehlo pebbles.morganco.com
250-mail1.sms-demag.de Hello pebbles.morganco.com ([216.47.36.83]),
pleased to meet you
250-HELP
250-DSN
250-SIZE 102400000
250 PIPELINING
mail from: hancocks@???
250 hancocks@???... Sender OK
rcpt to: konrad.roeingh@???
250 konrad.roeingh@???... Recipient OK
data
354 Enter message, end with "." on a line by itself
subject: another test from morganco.com
delete this
.
250 Message accepted for delivery
quit