correct template name

roles/smtpgateway/templates/main.cf.template

@@ -0,0 +1,37 @@
+# {{ansible_managed}}
+
+smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
+biff = no
+
+append_dot_mydomain = no
+
+readme_directory = no
+
+compatibility_level = 2
+
+smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
+smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
+smtpd_tls_security_level=may
+
+smtp_tls_CApath=/etc/ssl/certs
+smtp_sasl_auth_enable = yes
+smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
+smtp_sasl_security_options = noanonymous
+smtp_sasl_tls_security_options = noanonymous
+smtp_tls_security_level = encrypt
+header_size_limit = 4096000
+smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
+
+
+smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
+myhostname = {{ansible_hostname}}.{{external_domain}}
+alias_maps = hash:/etc/aliases
+alias_database = hash:/etc/aliases
+myorigin = /etc/mailname
+mydestination = {{ansible_hostname}}.{{external_domain}}, $myhostname, {{ansible_hostname}}, localhost.localdomain, localhost
+relayhost = {{postfix_relayhost}}
+mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
+mailbox_size_limit = 0
+recipient_delimiter = +
+inet_interfaces = all
+inet_protocols = all