----- Original Message ----- > From: "Wietse Venema" <wie...@porcupine.org> > To: "Postfix users" <postfix-users@postfix.org> > Sent: Saturday, January 23, 2016 9:57:40 AM > Subject: Re: Postfix Postscreen Pregreet Test
> Nguyen Nang Thang: >> > Postfix sends: >> > >> > 220-myhostname ESMTP >> > >> > Postfix waits $postscreen_greet_wait seconds. >> > Bad SMTP clients will greet before $postscreen_greet_wait seconds >> > have passed. >> > >> > 220 myhostname ESMTP >> > >> > Good SMTP clients will greet now. >> >> Wietse: >> Thanks for your detailed explain. Can you suggest me technical ways to >> manually >> test Bad SMTP clients >> that greet before $postscreen_greet_wait seconds have passed? > > echo whatever | nc host 25 Wietse: I dit my test as below: # nc localhost 25 < /tmp/postscreen-greet-wait.txt The output: 220 gw.mydomain.com ESMTP Postfix (2.10.1) 250 2.1.0 Ok 250 2.1.5 Ok 354 End data with <CR><LF>.<CR><LF> 250 2.0.0 Ok: queued as 35CA025E69 The postfix/postcreeen log does not show info "PREGREET count after time from [address]:port text...", test message delivered normally (expect: test message prevented by postscreen). So, is there another way to quickly make smtp connection via "nc" or another tool to test the parameter "postscreen_greet_wait"? Thanks. Regards, N. Thang