Postfix: Configure a SmartHost with SMTP Authentication and TLS.
A smart host is a type of mail relay server which allows an SMTP server to route e-mail to an intermediate mail server rather than directly to the recipient’s server. [Wikipedia]
This document aims to describe some simple steps to setup a Postfix eMail server with a SmartHost used to relay messages through. The SmartHost will be authenticated and secured trough TLS.
1. Create a password file in /etc/postfix/relay_password containing SMTP host, username and password (used for submission authentication) as shown:
smtp.relaydomain.ext USERNAME:PASSWORD |
2. Secure the file against unwanted modifications and readings:
chmod 600 /etc/postfix/relay_password |
3. Hash the file in order to create a passwords.db file
postmap /etc/postfix/relay_passwords |
4. Configure Postfix, by editing /etc/postfix/main.cf
relayhost = [smtp.relaydomain.ext]:587 smtp_use_tls=yes smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/relay_passwords smtp_sasl_security_options = 5. Check and then (if all seems to be ok) Reload postfix configuration <pre lang="bash"> postfix check postfix reload |
To have some debug:
tail -f /var/log/mail.log |