Il nostro punto della strada

In order to have a working SMTP server we have to take care of “some” ;) points:

• PTR reverse DNS record: dig +short ptr <reverse IP>.in-addr.arpa must give an hostname which DNS A record points to the <IP address> of your server.
• DNS:
  • MX → who exchange the mail for the domain?
  • SPF → which addresses can be originated from the MX?
  • DKIM → how are signed messages outgoing from the MX?
  • DMARC → what actions do you suggest to mail receivers' providers regarding the conf of SPF/DKIM and where you would like to receive reports from them to tune your mail settings?

• Furthermore we need working antispam and antivirus
• And of course SMTP server only relay local or TLS + authenticated connections
• Need to add DNS entries to the host that receives DMARC reports if domain is different from the one of the DMARC itself

• https://wiki.zimbra.com/wiki/Best_Practices_on_Email_Protection:_SPF,_DKIM_and_DMARC
• https://workaround.org/ispmail/jessie
• https://workaround.org/ispmail/wheezy/smtpd-restrictions-spf-dkim-and-greylisting
• DKIM on STMP RELAY server (trust hosts…) http://www.stevejenkins.com/blog/2011/08/installing-opendkim-rpm-via-yum-with-postfix-or-sendmail-for-rhel-centos-fedora/

• SPF: http://tools.wordtothewise.com/spf/check/
• SPF, DKIM, Antispam: http://dkimvalidator.com send an email to the given address and view results
• DMARC: https://dmarcian.com/
• IMAPs: http://wiki.dovecot.org/TestInstallation
• SMTP: https://www.ndchost.com/wiki/mail/test-smtp-auth-telnet
• SMTPs: https://www.saotn.org/tls-test-smtp-auth-plain-authentication-and-verify-starttls-connections/