Привет!
CentOS 7.3, Postfix 2.10.1
tail -f /var/log/maillog
Apr 17 10:03:19 site postfix/smtpd[24817]: connect from localhost[127.0.0.1]
Apr 17 10:03:19 site postfix/smtpd[24817]: smtp_stream_setup: maxtime=300 enable_deadline=0
Apr 17 10:03:19 site postfix/smtpd[24817]: match_hostname: localhost ~? 127.0.0.1
Apr 17 10:03:19 site postfix/smtpd[24817]: match_hostaddr: 127.0.0.1 ~? 127.0.0.1
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 220 site.ru ESMTP Postfix
Apr 17 10:03:19 site postfix/smtpd[24817]: watchdog_pat: 0x7f5305233f90
Apr 17 10:03:19 site postfix/smtpd[24817]: < localhost[127.0.0.1]: EHLO site.ru
Apr 17 10:03:19 site postfix/smtpd[24817]: match_list_match: localhost: no match
Apr 17 10:03:19 site postfix/smtpd[24817]: match_list_match: 127.0.0.1: no match
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250-site.ru
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250-PIPELINING
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250-SIZE 10240000
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250-VRFY
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250-ETRN
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250-ENHANCEDSTATUSCODES
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250-8BITMIME
Apr 17 10:03:19 site postfix/smtpd[24817]: > localhost[127.0.0.1]: 250 DSN
Apr 17 10:03:19 site postfix/smtpd[24817]: watchdog_pat: 0x7f5305233f90
Apr 17 10:03:19 site postfix/smtpd[24817]: smtp_get: EOF
Apr 17 10:03:19 site postfix/smtpd[24817]: match_hostname: localhost ~? 127.0.0.1
Apr 17 10:03:19 site postfix/smtpd[24817]: match_hostaddr: 127.0.0.1 ~? 127.0.0.1
Apr 17 10:03:19 site postfix/smtpd[24817]: lost connection after EHLO from localhost[127.0.0.1]
Apr 17 10:03:19 site postfix/smtpd[24817]: disconnect from localhost[127.0.0.1]
systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2017-04-14 17:33:06 +09; 2 days ago
getenforce
Enforcing
Спасибо за ответы :-)