Training per sysadmin

Verifica raggiungibilità host

Prima di tutto si deve verificare se si raggiunge il sistema remoto. Si può fare con il programma `ping <nome host o indirizzo IP>`

Il ping può essere utile per verificare anche la latenza di rete

Verifica raggiungibilità di un servizio

Esempio HTTP

TODO Costin

Esempio SSH

TODO Costin

Esempio SMTP (invio email)

TODO Costin

SMTP (avanzato)

Da non leggere se non si è già amministratori di un server email.

SMTP configuration

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

References

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/

Very useful thread for MS hotmail and outlook problems https://www.hmailserver.com/forum/viewtopic.php?t=27930

SMTP/IMAPs tests

Fantastic and happy! http://www.mail-tester.com/web-us64b

MX Toolbox non ha bisogno di presentazioni, molti test: https://mxtoolbox.com/

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/

Migrazione di un sistema di posta con soli alias verso Mailcow

<input type="checkbox" /> Backup e aggiornamento Mailcow

<input type="checkbox" /> Configurazione Mailcow → aggiungere dominio

<input type="checkbox" /> Creare un utente admin specifico per il dominio

<input type="checkbox" /> Trasferire alias

<input type="checkbox" /> Visualizzare tutte le impostazioni necessarie del DNS

<input type="checkbox" /> Effettuare il test: tra tutti mail-tester e mxtoolbox

Backup e aggiornamento

cd /opt/mailcow-dockerized
helper-scripts/backup_and_restore.sh backup all
./upgrade.sh
./upgrade.sh

Per il changelog v. canale Telegram, oppure git log