On Thu, Dec 05, 2013 at 08:23:18AM +0100, Matteo Cazzador wrote: > " hostname ... server refused to talk to me: 550 Denied by policy"
http://www.postfix.org/postconf.5.html#smtp_skip_5xx_greeting Note, some time ago there were systems (perhaps Microsoft Exchange) that returned 5xx codes in the SMTP banner due to high load (rather than a permanent error condition). They may still be present in sufficient numbers to make defer on 5xx banner the safer choice. > My problem is that the sender isn't warned of mail server error. > > The sender don't receive immediatly any error message, why? http://www.postfix.org/postconf.5.html#smtp_skip_5xx_greeting -- Viktor.