response: 554

some smtp's denied delivering of mails, here the log message:

Attempting delivery of Mail1196176785082-2-to-web.de to host mx-ha02.web.de. at 217.72.192.188 for addresses [xy@web.de]
27/11/07 16:19:45 INFO  James.Mailet: RemoteDelivery: Could not connect to SMTP host: 217.72.192.188, port: 25, response: 554
27/11/07 16:19:45 INFO  James.Mailet: RemoteDelivery: Temporary exception delivering mail (Mail1196176785082-2-to-web.de:
27/11/07 16:19:45 INFO  James.Mailet: RemoteDelivery: Storing message Mail1196176785082-2-to-web.de into outgoing after 0 retries

this smtp does not work, but some works such a gmx.net