When connecting to SMPT, it gives an error - Unable to connect to remote host: Connection timed out. Why?

Question

Plesk

As a test, I tried to connect to my mail server via telnet, but I get the following error:
telnet Unable to connect to remote host: Connection timed out
What do I need to change on the mail server so that I can connect via smtp?
I am using the plesk panel.
Below is the postfix config:

# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = /usr/share/doc/postfix/README_FILES

# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
# fresh installs.
compatibility_level = 2

# TLS parameters
smtpd_tls_cert_file = /etc/postfix/postfix.pem
smtpd_tls_key_file = $smtpd_tls_cert_file
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = mail.weblist.es
alias_maps = hash:/etc/aliases, hash:/var/spool/postfix/plesk/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = localhost.localdomain, localhost.localdomain, localhost
relayhost =
mynetworks = , 127.0.0.0/8
mailbox_size_limit = 0
recipient_delimiter =
inet_interfaces = all
inet_protocols = all
mydomain = localdomain
virtual_mailbox_domains = $virtual_mailbox_maps, hash:/var/spool/postfix/plesk/virtual_domains
virtual_alias_maps = $virtual_maps, hash:/var/spool/postfix/plesk/virtual
virtual_mailbox_maps = , hash:/var/spool/postfix/plesk/vmailbox
transport_maps = , hash:/var/spool/postfix/plesk/transport
smtpd_tls_security_level = may
smtp_tls_security_level = may
smtp_use_tls = no
smtpd_timeout = 3600s
smtpd_proxy_timeout = 3600s
disable_vrfy_command = yes
smtpd_sender_restrictions = check_sender_access hash:/var/spool/postfix/plesk/blacklists,permit_sasl_authenticated
smtpd_client_restrictions = permit_mynetworks, permit_sasl_authenticated
authorized_flush_users =
authorized_mailq_users =
smtp_send_xforward_command = yes
smtpd_authorized_xforward_hosts = 127.0.0.0/8 [::1]/128
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
virtual_mailbox_base = /var/qmail/mailnames
virtual_uid_maps = static:30
virtual_gid_maps = static:31
smtpd_milters = , inet:127.0.0.1:12768
sender_dependent_default_transport_maps = hash:/var/spool/postfix/plesk/sdd_transport_maps
virtual_transport = plesk_virtual
plesk_virtual_destination_recipient_limit = 1
mailman_destination_recipient_limit = 1
message_size_limit = 31457280
virtual_mailbox_limit = 0
smtpd_tls_ciphers = medium
smtpd_tls_mandatory_ciphers = medium
tls_medium_cipherlist = ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
smtpd_tls_mandatory_protocols = TLSv1.2
smtpd_tls_protocols = TLSv1.2
recipient_canonical_maps = tcp:127.0.0.1:12346
recipient_canonical_classes = envelope_recipient,header_recipient
daemon_directory = /usr/lib/postfix/sbin
queue_directory = /var/spool/postfix
meta_directory = /etc/postfix
setgid_group = postdrop
command_directory = /usr/sbin
sample_directory = /usr/share/doc/postfix/samples
newaliases_path = /usr/bin/newaliases
mailq_path = /usr/bin/mailq
sendmail_path = /usr/sbin/sendmail
mail_owner = postfix
manpage_directory = /usr/share/man
html_directory = no
data_directory = /var/lib/postfix
#shlib_directory = no
tls_server_sni_maps = hash:/var/spool/postfix/plesk/certs
tls_preempt_cipherlist = yes

Answer 1

Connection timed out

It says that it didn’t reach L7, the problem is at the L4 level, i.e. ports are closed. Either the incoming tcp/25 port, or from the machine from which the telnet is being tried, outgoing requests to the tcp/25 port are closed.