This is the Postfix program at host lin-mx.df-webhosting.de.

I'm sorry to have to inform you that your message could not be
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

			The Postfix program

<xyz@t-online.de>: host mx02.t-online.de[194.25.xxx.x] said: 500 5.6.1 Line
    too long. (in reply to end of DATA command)

Reporting-MTA: dns; lin-mx.df-webhosting.de
X-Postfix-Queue-ID: 5BBF99789CE
X-Postfix-Sender: rfc822; newsletter@xxxxxxxx.com
Arrival-Date: Fri,  9 Jan 2015 08:42:50 +0100 (CET)

Final-Recipient: rfc822; xyz@t-online.de
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; host mx02.t-online.de[194.25.xxx.x] said: 500 5.6.1
    Line too long. (in reply to end of DATA command)