Problems with setting up mail for Сentos, Postfix, Dovecot

Question

postfix

Can't connect to mail for n...th day.
Installed Postfix, Dovecot.
There is silence in the logs. There are no errors.
First things first :
For example, connecting to the server mail.server.com (IP:177.777.777.777)
Microsoft Telnet> open mail.server.com 25
Connecting to mail.server.com... Could not open a connection to this host , on Microsoft Telnet
If checked against the server:
telnet localhost 25
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 mail.server.com ESMTP Postfix
user ... login ... etc. next OK
For example, if you send a letter to the mailbox [email protected] , the
letter will not be delivered:
Final Recipient: rfc822; [email protected]
Original-Recipient: rfc822;[email protected]
Action: failed
Status: 5.1.1
Diagnostic-Code: x-unix; username
.................................................................. ................................................
Log /var/log/maillog:
Feb 13 00:48:21 server dovecot: imap-login: Login: user=, method=PLAIN, rip=::1, lip=::1, mpid=397, secured
Feb 13 00:48:21 server dovecot: imap( [email protected]): Disconnected: Logged out bytes=79/687
Feb 13 00:50:01 server dovecot: imap-login: Disconnected (no auth attempts): rip=::1, lip=::1, secured
Feb 13 00:50:01 server dovecot: pop3-login: Disconnected (no auth attempts): rip=::1, lip=::1, secured
Feb 13 00:50:01 server postfix/smtpd[448]: connect from localhost[::1]
Feb 13 00:50:01 server postfix/smtpd[448]: lost connection after CONNECT from localhost[::1]
Feb 13 00:50:01 server postfix/smtpd[448]: disconnect from localhost[::1]
............................ .................................................
]# netstat -atnp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:587 0.0.0.0:* LISTEN 31395/master
tcp 0 0 0.0 .0.0:110 0.0.0.0:* LISTEN8820/dovecot
tcp 0 0 0.0.0.0:143 0.0.0.0:* LISTEN 8820/dovecot tcp
0 0 0.0.0.0:80 0.0.0.0:* LISTEN 2210/nginx
nginx
tcp 0 0 0.0.0.0:8081 0.0.0.0:* LISTEN 2210/nginx
tcp 0 0 127.0.0.1:9011 0.0.0.0:* LISTEN 2186/php-fpm
tcp 0 0 127.0.0.1:9013 0.0.0.0:* LISTEN 2186/php-fpm
tcp 0 0 0.0.0.0:21 0.0.0.0:* LISTEN 1459/vsftpd
tcp 0 0 177.777.777.777:53 0.0.0.0:* LISTEN 1349/named
tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 1349/
named sshd
tcp 0 0 127.0.0.1:9015 0.0.0.0:* LISTEN 2186/php-fpm
tcp 0 0 0.0.0.0:25
0.0.0.0:* LISTEN 1349/named
tcp 0 0 0.0.0.0:993 0.0.0.0:* LISTEN 8820/dovecot
tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 8820/
dovecot
tcp 0 0 127.0.0.1:10024 0.0.0.0:* LISTEN 2186/php-fpm tcp
0 0 127.0.0.1:10025 0.0.0.0:*
LISTEN
:54909 ESTABLISHED 30987/sshd
tcp 0 0 177.777.777.777:22 77.120.171.17:56762 ESTABLISHED 1120/sshd
TCP 0 0 127.0.0.1:30216 127.0.0.1:3306 Established 9211 / Amavisd (CH10- TCP
0 0 177.777.777.777:22 77.120.171.17:4908 Established 30885 / SSHD TCP
0 0 127.0.0.1:3306 127.0.0.1:29685 Established 2018 /
MySQLD TCP 0 0 177.777.777.777:8080 77.120.171.17:8080 77.120.171.17:59266 Time_Wait - TCP
0 0 127.0.0.1:3306 127.0.0.1:30216 Established 2018 / MySqld TCP
0 0 127.0.0.1:29685 127.0.0.1:3306 Established 9210/amavisd (ch10-
tcp 0 0 :::587 :::* LISTEN 31395/master
tcp 0 0 :::110 :::* LISTEN 8820/dovecot
tcp 0 0 :::143 :::* LISTEN 8820/dovecot
tcp 0 0 :::22 :::* LISTEN 1448/sshd
tcp 0 0 :: :25 :::* LISTEN 31395/master
tcp 0 0 :::993 :::* LISTEN 8820/dovecot
tcp 0 0 :::995 :::* LISTEN 8820/dovecot
tcp 0 0 ::1:25 :: 1:14949 ESTABLISHED 32590/smtpd
tcp 0 0 ::1:14949 ::1:25 ESTABLISHED 32589/telnet

Answer 1

Maybe port 25 is blocked.
Try using 587 for SMTP, check it first with telnet.