Postfix adalah suatu software open-source yang berfungsi sebagai MTA (Mail Transfer Agent) yang digunakan untuk mengirim, menerima, dan memfilter email, Cara Postfix berkomunikasi yakni menggunakan protocol SMTP.

Postfix berguna untuk send email ke mail server, contoh seperti mail company, gmail ataupun lainnya.

Setting Postfix

  • Install dependencies

    apt update
apt install -y libsasl2-modules mailutils

  • Setting App Password pada Google Account jika menggunakan gmail (Optional)

    https://myaccount.google.com/apppasswords

  • Set User & password email

    #Gmail
echo "smtp.gmail.com your-email@gmail.com:YourAppPassword" > /etc/postfix/sasl_passwd

#Mail server pribadi
echo "mail.example.com your-email@example.com:YourPassword" > /etc/postfix/sasl_passwd

  • Update permissions and hash the file

    chmod 600 /etc/postfix/sasl_passwd
postmap hash:/etc/postfix/sasl_passwd

#Check hash
cat /etc/postfix/sasl_passwd.db

  • Edit postfix config

    -> nano /etc/postfix/main.cf

# google mail configuration
relayhost = smtp.gmail.com:587

# Mail server pribadi
relayhost = mail.example.com:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_security_options =
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd.db
smtp_tls_CAfile = /etc/ssl/certs/Entrust_Root_Certification_Authority.pem
smtp_tls_session_cache_database = btree:/var/lib/postfix/smtp_tls_session_cache
smtp_tls_session_cache_timeout = 3600s

  • Reload Postfix

    postfix reload

  • Test Send Email

    echo "This is a test message sent from postfix on my Proxmox Server" | mail -s "Test Email from Proxmox" user@gmail.com

Change from name in email

Before

Before

After

After

  • install dependency

    -> apt update
-> apt install postfix-pcre

  • Edit config

    -> nano /etc/postfix/smtp_header_checks
#mail isi hostname server yang sudah di setting di /etc/postfix/main.cf
/^From:.*/ REPLACE From: pve1-alert <pve1-alert@pve.example.com>

  • Hash the file

    -> postmap hash:/etc/postfix/smtp_header_checks

#Check hash
-> cat /etc/postfix/smtp_header_checks.db

  • Add the module to postfix config

    nano /etc/postfix/main.cf

#add to the end of the file
smtp_tls_session_cache_timeout = 3600s
smtp_header_checks = pcre:/etc/postfix/smtp_header_checks

  • Reload Postfix

    postfix reload

  • Test Send Email

    echo "This is a test message sent from postfix on my Proxmox Server" | mail -s "Test Email from Proxmox" user@gmail.com

Reference :