Hi,all: I am a beginner of qmail. I want to know how to generate the deferral messags as follows: Jan 19 19:00:58 **** qmail: 948279658.032706 delivery 14154: deferral: Connect ed_to_193.79.81.224_but_sender_was_rejected./Remote_host_said:_451_<***@***>..._Sender_domain_must_resolve/ Thank you for your reply! zhjyu Thank you for using the km169.net