Gambar gembok merah di gmail, bila dicek pesannya kira-kira domain.com did not encrypt this message
Solusi
Bila anda belum menyetting SSL bisa menggunakan self-signed ataupun commercial SSL (Comodo, Symantec, Geotrust), disini kita akan menggunakan self-signed SSL.
mkdir /etc/postfix/ssl; cd /etc/postfix/ssl; openssl req -x509 -nodes -newkey rsa:2048 -keyout mail.DOMAIN.com.key -out mail.DOMAIN.com.crt -nodes -days 3650
di /etc/postfix/main.cf tambahkan
smtpd_use_tls = yes smtpd_tls_auth_only = yes smtpd_tls_cert_file = /etc/postfix/ssl/mail.DOMAIN.com.crt smtpd_tls_key_file = /etc/postfix/ssl/mail.DOMAIN.com.key smtpd_tls_mandatory_protocols=!SSLv2,!SSLv3 smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache # bagian ini yang sign email smtp_tls_security_level = may smtpd_tls_security_level = may smtp_tls_note_starttls_offer = yes
restart postfix lalu kirim ulang email anda.
