Mail has 'Auto-Submitted: auto-generated' header - won't respond to it

[borussemd]

Hi
if we get mails from the contact us form we are unable to set a autoresponder to them.
Received Mails seems to have the correct Sender Adress.
Our provider send us these logs:

Feb 6 09:42:53 host261 autoresponder[2075772]: C2D64280AE1: Mail has 'Auto-Submitted: auto-generated' header - won't respond to it.
Feb 6 09:42:53 host261 postfix-local[2075771]: C2D64280AE1: autoresponder: stderr: PASS
Feb 6 09:42:53 host261 dk_check[2075773]: C2D64280AE1: DKIM Feed: No signature
Feb 6 09:42:53 host261 postfix-local[2075771]: C2D64280AE1: dk_check: stderr: PASS
Feb 6 09:42:53 host261 postfix/pipe[2075770]: C2D64280AE1: to=<ibvnffax2@mi-forum.net>, orig_to=<support@mi-forum.net>, relay=plesk_virtual, delay=0.54, delays=0.45/0.01/0/0.08, dsn=2.0.0, status=sent (delivered via plesk_virtual service)
Feb 6 09:42:53 host261 postfix/qmgr[2066046]: C2D64280AE1: removed

Where are my error?