550 Administrative prohibition (in reply to DATA command) on OOO-Mails

When I send a mail to an external recipient and he replys with an Out Of Office-Mail, our postfix (which manage our incoming Mails) can't forward it to sophos utm.

Log-Entry: status=bounced (host sophos.xxxxxx.de[<IP>] said: 550 Administrative prohibition (in reply to DATA command))

 

What's bad configured in my UTM?

 

Best Regards

Denis