In mail.log I see:
postfix/smtpd[27414]: connect from unknown[NN.NN.NN.NN]
postfix/smtpd[27414]: lost connection after CONNECT from unknown[NN.NN.NN.NN]
postfix/smtpd[27414]: disconnect from unknown[NN.NN.NN.NN]
As I wrote telnet to 25 works as expected, but to 587 is closed after initial greeting.
Wireshark on client side shows me TCP RST packet ir received...
This is for particular IP, not depending on OS, router.
Any ideas?
Thank You