StefanoStrozzi.it

apt-get install postfix

nelle ultime prove fatte il 04-06-16 ho già installato apache php5 e mysql-server, si dovrebbe installare anche postfix-mysql, ma ho provato a lanciare solo apt-get install postifx e automaticamente ha suggerito anche postifx-mysql.
In realtà non lo installa e quindi sarebbe meglio installarli insieme con:

apt-get install postfix postfix-mysql

Comunque avviata l'installazione parte subito lo script per la configurazione di base e quindi chiede che tipo di configurazione, e noi scegliamo “sito internet”; poi il servername e noi per ora mettiamo l'hostname che è il classico nome dell'host (nel mi ocaso metto “mail”). Ma non ho ancora ben capito il legame che c'è tra il “system mail name” il “nome host” e il “FQDN” che penso centri qualcosa con il MX record del DNS e il fatto che la mail di google (GMAIL) se non trova le cose coordinate non ti manda la posta e se tu gliela mandi ti schifa.
Bohh? devo approfondire.
Per ora metto durante la configurazione “mail”.

apt-cache show postfix

Package: postfix
Version: 2.11.3-1
Installed-Size: 2873
Maintainer: LaMont Jones <lamont@debian.org>
Architecture: armhf
Replaces: mail-transport-agent
Provides: mail-transport-agent
Depends: libc6 (>= 2.11), libdb5.3, libsasl2-2, libsqlite3-0 (>= 3.5.9), libssl1.0.0 (>= 1.0.0), debconf (>= 0.5) | debconf-2.0, netbase, adduser (>= 3.48), dpkg (>= 1.8.3), lsb-base (>= 3.0-6), ssl-cert, cpio
Recommends: python
Suggests: procmail, postfix-mysql, postfix-pgsql, postfix-ldap, postfix-pcre, sasl2-bin, libsasl2-modules, dovecot-common, resolvconf, postfix-cdb, mail-reader, ufw, postfix-doc
Conflicts: libnss-db (<< 2.2-3), mail-transport-agent, smail
Description-en: High-performance mail transport agent
 Postfix is Wietse Venema's mail transport agent that started life as an
 alternative to the widely-used Sendmail program.  Postfix attempts to
 be fast, easy to administer, and secure, while at the same time being
 sendmail compatible enough to not upset existing users. Thus, the outside
 has a sendmail-ish flavor, but the inside is completely different.
Description-md5: 98656fbf1bb45b53edd367037a2e5a90
Homepage: http://www.postfix.org
Tag: implemented-in::c, interface::daemon, mail::smtp, mail::transport-agent,
 network::server, protocol::smtp, role::program, works-with::mail
Section: mail
Priority: extra
Filename: pool/main/p/postfix/postfix_2.11.3-1_armhf.deb
Size: 1311022
MD5sum: 3bbf12e780bca67418e3bb8ca6662742
SHA1: 42894ad6a408ec9df2f11ef6262584a5bef3ca52
SHA256: dc2e51df6cdf93f01d975ff8f306c58280ba23a0675e23994cda8e76ed6ba839

Non l'avevo mai fatto, ma se io lancio dpkg-reconfigure postfix parte una procedura che mi guida nella modfica del file main.cf.
L'ho fatto ma è meglio evitare per il mio caso.

configurazione di postfix

di seguito i file già pronti per me.

/etc/postfix/main.cf

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no
 
append_dot_mydomain = no
 
readme_directory = no
 
smtpd_tls_cert_file=/etc/dovecot/dovecot.pem
smtpd_tls_key_file=/etc/dovecot/private/dovecot.pem
 
smtpd_use_tls=yes
smtpd_tls_auth_only = no
#smtpd_tls_security_level = may
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
 
smtpd_recipient_restrictions =permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination
 
myhostname = mail
 
alias_maps = hash:/etc/aliases
 
alias_database = hash:/etc/aliases
 
mydestination = 127.0.0.1
 
relayhost =
mynetworks = 127.0.0.0/8
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = ipv4
 
virtual_transport=lmtp:unix:private/dovecot-lmtp
 
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf

Per bloccare ip che cercano continuamente di connettersi

iptables -A INPUT -s 1.52.125.2 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 2.59.118.0/24 -p tcp --destination-port 25 -j DROP 
iptables -A INPUT -s 2.59.119.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 2.179.62.84 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 2.229.92.112 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 5.40.56.34 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 5.188.70.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 5.188.168.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 5.188.206.0/24 -p tcp --destination-port 25 -j DROP  
iptables -A INPUT -s 5.188.206.0/24 -p tcp --destination-port 587 -j DROP  
iptables -A INPUT -s 5.189.0.0/16 -p tcp --destination-port 25 -j DROP  
iptables -A INPUT -s 14.176.231.141 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 14.176.231.112 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 14.176.232.119 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 23.228.150.114 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 23.247.70.121 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 23.254.0.0/16 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 27.74.241.212 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 31.45.240.222 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.6.93.126 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.46.150.167 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.49.224.102 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.49.225.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.49.227.130 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.49.230.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.97.187.209 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.114.129.96 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.114.141.149 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.114.190.144 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.131.169.80 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.157.255.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.159.236.6 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.182.202.130 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.208.61.245 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.212.33.121 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 37.221.213.146 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 38.70.235.231 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 40.73.246.16 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 41.72.208.130 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 41.80.141.197 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 41.225.139.103 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 41.225.239.103 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 42.112.227.158 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 42.113.196.170 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 42.117.240.158 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 43.241.80.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.8.124.0/24 -p tcp --destination-port 25 -j DROP  
iptables -A INPUT -s 45.8.126.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.8.126.0/24 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 45.13.39.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.13.39.0/24 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 45.82.153.37 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.82.153.76 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.82.153.133 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.125.64.0/22 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.125.164.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.141.87.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.142.195.5 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.146.166.111 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.148.10.182 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.224.163.67 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 45.227.253.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 46.33.39.34 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 46.38.144.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 46.38.148.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 46.38.150.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 46.151.73.63 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 46.161.54.194 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 50.3.73.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 51.68.121.167 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 51.75.253.11 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 51.159.22.125 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 51.252.143.151 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 51.254.131.137 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 52.101.128.66 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 54.39.244.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 59.45.171.158 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 60.2.137.171 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 60.246.0.51 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 61.106.26.247 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 61.106.26.247 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 61.183.219.6 -p tcp --destination-port 25 -j DROP  
iptables -A INPUT -s 62.1.193.238 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 62.28.92.226 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 62.36.20.210 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 62.50.131.54 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 62.60.206.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 62.84.83.226 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 62.210.24.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 62.210.28.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 63.219.187.0/24 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 63.219.187.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 66.70.205.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 67.215.225.119 -p tcp --destination-port 25 -j DRO
iptables -A INPUT -s 70.96.202.71 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 72.204.164.109 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 72.204.164.109 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 75.188.240.11 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 77.72.82.124 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 77.244.214.149 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 77.246.15.12 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.5.130.201 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.7.98.10 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.15.109.2 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.83.98.20 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.128.113.121 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.128.113.131 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.155.206.173 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.155.206.237 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.190.191.173 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 78.219.125.15 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 79.3.129.135 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 79.3.221.22 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 79.9.72.148 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 79.10.53.113 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 80.19.154.154 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 80.21.190.42 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 80.58.144.149 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 80.82.0.0/16 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 80.82.0.0/16 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 80.90.129.66 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 80.253.244.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 81.22.255.141 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 81.93.86.149 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 81.130.210.19 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 82.117.198.158 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 82.166.184.188 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 82.185.145.249 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 82.193.10.254 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 83.211.10.27 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 84.127.69.18 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 84.237.86.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 85.119.144.42 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 85.195.73.99 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 85.202.81.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 85.202.82.0/23 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 87.26.79.238 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 87.120.36.244 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 87.246.7.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 87.246.7.0/24 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 86.104.72.51 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 88.36.118.219 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 88.41.109.99 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 88.149.228.191 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 88.205.135.21 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 89.29.162.214/24 -p tcp --destination-port 25 -j DROP     
iptables -A INPUT -s 89.163.129.0/24 -p tcp --destination-port 25 -j DROP     
iptables -A INPUT -s 89.163.130.0/24 -p tcp --destination-port 25 -j DROP     
iptables -A INPUT -s 89.163.139.0/24 -p tcp --destination-port 25 -j DROP 
iptables -A INPUT -s 89.207.169.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 89.248.168.62 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 89.248.171.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 89.248.172.85 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 89.252.133.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 90.179.167.60 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 90.179.168.60 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 91.142.222.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 91.148.137.53 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 91.212.150.89 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 91.212.150.128 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 91.212.150.158 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 91.234.99.230 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 91.241.51.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 92.38.176.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 92.118.61.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 92.246.76.92 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 92.247.22.68 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 92.247.60.103 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.42.137.151 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.46.193.98 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.57.50.74 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.61.93.92 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.71.169.51 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.142.237.3 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.157.62.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.157.63.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 93.157.63.30 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 94.74.129.163 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 94.74.184.168 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 94.102.56.215 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 94.102.50.103 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 94.138.40.214 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 94.185.81.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 94.200.120.238 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 94.236.167.10 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 95.141.27.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 95.142.139.148 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 95.213.235.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 95.234.63.230 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 96.75.195.171 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 102.68.77.74 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 102.165.32.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 102.165.52.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.40.202.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.89.88.64 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.99.2.73 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.125.191.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.133.109.36 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.207.37.40 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.208.246.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.231.139.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.240.194.43 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 103.247.197.1 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 104.145.227.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 104.150.20.54 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 104.161.20.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 104.168.0.0/16 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 104.206.128.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 105.67.10.10 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 105.228.232.212 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 106.75.79.172 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 107.172.193.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 108.59.241.10 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 108.174.196.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 109.108.140.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 109.164.204.72 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 109.169.72.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 109.196.36.22 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 109.196.241.145 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 109.235.51.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 112.26.187.155 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 113.23.27.7 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 113.106.11.57 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 114.124.193.71 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 114.249.0.172 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 115.78.14.153 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 117.121.238.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 118.70.118.173 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 118.201.230.160 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 121.117.166.163 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 122.215.71.15 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 123.125.50.138 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 123.200.137.226 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 125.199.208.134 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 125.209.85.196 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 130.193.122.217 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 134.73.87.176 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 134.119.204.243 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 137.59.161.177 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 139.28.36.10 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 141.98.9.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 141.98.10.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 141.98.80.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 142.11.192.0/18 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 144.217.0.0/16 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 145.14.133.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 147.253.216.113 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 149.56.177.168 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 149.56.189.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 149.210.126.54 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 150.145.11.129 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 151.15.199.221 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 151.45.251.17 -p tcp --destination-port 25 -j DROP  
iptables -A INPUT -s 151.73.195.100 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 151.106.0.55 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 151.106.17.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 157.52.214.116 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 159.253.34.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 160.152.29.50 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 163.123.244.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 164.52.24.172 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 164.52.24.172 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 165.231.143.241 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 166.251.247.29 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 167.114.74.105 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 168.90.71.82 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 168.205.108.42 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 170.130.143.121 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 172.106.37.144 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 173.225.101.110 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 174.139.156.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 176.31.238.116 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 176.98.42.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 176.105.232.2 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 176.233.140.118 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 177.6.121.235 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 177.37.166.119 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 177.125.214.90 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 177.189.204.86 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 177.241.63.60 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 173.225.99.105 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 178.159.36.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 178.16.162.98 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 178.73.215.171 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 179.6.222.176 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 179.41.26.133 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 179.189.87.45 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 181.143.248.58 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 181.214.143.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 182.156.215.86 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 182.233.74.206 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 184.164.70.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.35.63.161 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.36.81.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.39.161.182 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.66.143.213 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.88.173.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.130.56.195 -p tcp --destination-port 25 -j DROP 
iptables -A INPUT -s 185.136.160.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.137.111.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.142.0.0/16 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.143.72.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.143.73.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.143.75.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.138.188.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.156.177.136 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.157.230.161 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.162.147.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.170.209.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.184.24.219 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.211.245.170 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.211.245.198 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.222.209.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.225.36.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.228.80.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.234.216.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.234.217.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.234.218.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.234.219.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.254.52.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.254.53.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 185.254.236.0/22 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 186.96.111.11 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 186.122.164.4 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 186.225.120.42 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 187.19.177.10 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 187.107.136.134 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 187.189.53.87 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 188.68.208.158 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 188.166.42.50 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 188.246.227.183 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 189.114.224.250 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 190.100.30.82 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 190.104.119.191 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 190.116.21.154 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 190.128.186.98 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 190.153.220.42 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 190.162.201.190 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 190.197.96.44 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 191.53.16.236 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 191.96.45.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.99.27.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.99.81.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.99.214.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.119.65.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.119.67.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.119.71.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.236.162.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.241.219.158 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 192.241.227.41 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.17.6.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.56.28.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.57.40.242 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.169.28.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.169.252.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.169.254.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.84.64.100/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.193.183.71 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.233.0.0/16 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 193.238.47.226 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.28.34.96 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.28.222.15 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.36.142.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.62.54.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.62.55.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.110.87.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.126.237.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.145.139.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.156.126.20 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 194.244.9.39 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 195.31.160.148 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 195.103.195.195 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 196.28.75.164 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 197.14.12.36 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 197.157.0.34 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 198.50.17.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 198.144.138.3 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 200.52.77.57 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 200.57.73.170 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 200.60.30.19 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 200.68.123.216 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 200.174.238.50 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 201.161.11.45 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 201.217.144.21 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 201.236.155.138 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 201.249.158.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 202.29.95.141 -p tcp --destination-port 587 -j DROP
iptables -A INPUT -s 202.137.141.183 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 203.2.118.242 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 207.126.164.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 207.228.248.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 208.76.54.0/24 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 209.85.218.73 -p tcp --destination-port 25 -j DROP  
iptables -A INPUT -s 212.16.186.36 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 212.70.149.0/24 -p tcp --destination-port 25 -j DROP  
iptables -A INPUT -s 213.82.62.162 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 213.137.43.14 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 214.144.77.146 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 217.5.219.18 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 217.141.159.106 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 217.170.124.88 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 217.194.186.53 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 218.227.158.181 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 220.120.241.209 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 222.161.221.230 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 223.72.116.89 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 5.199.143.126 -p tcp --destination-port 25 -j DROP     
iptables -A INPUT -s 85.114.138.0/24 -p tcp --destination-port 25 -j DROP    
   
 
  

Tentativi di accesso falliti e bloccati

202.238.114.111  giappone
189.115.43.96    brasile
warning: unknown[141.98.80.16]: SASL PLAIN authentication failed:   panama

Per capire se c'è qualcuno che prova ad autenticarsi ripetutamente eseguire:

cat /var/log/mail.log |grep "SASL PLAIN authentication failed"

Si avrà un esito tipo questo:

root@n2:/home/stefano# cat /var/log/mail.log |grep "SASL PLAIN authentication failed"
Feb 20 00:10:30 n2 postfix/smtpd[16374]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 00:10:38 n2 postfix/smtpd[23433]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 00:57:35 n2 postfix/smtpd[26867]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 00:57:44 n2 postfix/smtpd[16374]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 03:09:05 n2 postfix/smtpd[13636]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 03:09:13 n2 postfix/smtpd[23941]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 04:04:23 n2 postfix/smtpd[17476]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 04:04:31 n2 postfix/smtpd[17476]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 04:27:14 n2 postfix/smtpd[7332]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 04:27:29 n2 postfix/smtpd[17476]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 04:27:32 n2 postfix/smtpd[17476]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:
Feb 20 05:17:58 n2 postfix/smtpd[25638]: warning: unknown[185.222.209.61]: SASL PLAIN authentication failed:

E' evidente che qualcuno dall'ip 185.222.209.61 prova ripetutamente a loggarsi fallendo.
Per chiudergli definitivamente la porta uso iptables nel seguente modo:

iptables -A INPUT -s 185.222.209.61 -p tcp --destination-port 25 -j DROP
iptables -A INPUT -s 141.98.80.16 -p tcp --destination-port 25 -j DROP

per verificare abusi:
https://www.abuseipdb.com/check/80.58.144.149