Same problem here sending mails to bluewin for weeks now.
Mails sent from our Server to bluewin get a (conversation with mxbw.bluewin.ch[195.186.19.144] timed out while sending end of data -- message may be sent more than once)
Server: 212.103.79.230 FQDN: ns1.scnat.ch
Any solution on this?
thanks in advance, stef