Postfix for Docker
Small image (~ 4MB) for Postfix based on Alpine. This image is only for outgoing messages and allows connection to the SMTP server from private networks (10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16) without authentication.
Environment variables
POSTFIX_DOMAIN
Set the domain name. Also sets the host name in the e-mail address if the host name is not an FQDN.
POSTFIX_RELAYHOST
The relayhost parameter specifies the default host to send mail
POSTFIX_SMTP_TLS_SECURITY_LEVEL
Set the default security level for outgoing mails.
- POSTFIX_SMTP_TLS_SECURITY_LEVEL="may"
Valid levels are none, may, encrypt, … see http://www.postfix.org/postconf.5.html#smtp_tls_security_level
Default: may
POSTFIX_SMTP_TLS_POLICY_MAPS
Override the default security level for outgoing mails per domain.
-e POSTFIX_SMTP_TLS_POLICY_MAPS="foo.example.com encrypt\nbar.example.com may"
Valid levels are none, may, encrypt, … see http://www.postfix.org/postconf.5.html#smtp_tls_security_level
http://www.postfix.org/postconf.5.html#smtp_tls_policy_maps
Volumes
/var/spool/postfix
To keep the unsent emails even when the container is restarted, create a volume
for /var/spool/postfix.