Replacing the default FreeBSD system mailer Sendmail with Postfix using SMTP AUTH, acting as mail client

Postfix-SASL-client.md

Replacing the default FreeBSD system mailer Sendmail with Postfix using SMTP AUTH, acting as mail client

Replacing Sendmail with Postfix

# pkg install postfix-sasl¹

Would you like to activate Postfix in /etc/mail/mailer.conf [n]? y²

# service sendmail stop

# sysrc postfix_enable="YES"
# sysrc sendmail_enable="NONE"

# echo '# Disable sendmail(8) specific tasks\
daily_clean_hoststat_enable="NO"\
daily_status_mail_rejects_enable="NO"\
daily_status_include_submit_mailq="NO"\
daily_submit_queuerun="NO"\
#' >> /etc/periodic.conf

---

1: To use SASL authentication Postfix needs be built with Cyrus SASL support.

2: If you skipped this step and Postfix is not already activated in /etc/mail/mailer.conf :

# mv /etc/mail/mailer.conf /etc/mail/mailer.conf.old
# install -m 0644 /usr/local/share/postfix/mailer.conf.postfix /etc/mail/mailer.conf

Configuring SASL authentication in the Postfix SMTP client

Make sure Postfix built with SASL:

# postconf -A
cyrus

Create $config_directory/sasl_passwd:

[smtp.example.com]:submission username:password

# postmap sasl_passwd

Add to main.cf:

# SASL authentication in the Postfix SMTP client
smtp_sasl_auth_enable = yes
relayhost = [smtp.example.com]:submission
smtp_sasl_password_maps = hash:$config_directory/sasl_passwd

# service postfix start

Configuring TLS (optional)

To enable opportunistic TLS add to main.cf:

smtp_tls_security_level = may

Testing

> telnet localhost 25

...

mail from: <user@example.com>

250 2.1.0 Ok

rcpt to: <user1@example1.com>

250 2.1.5 Ok

data

354 End data with <CR><LF>.<CR><LF>

To: <user1@example1.com>

From: <user@example.com>

Subject: Test

Message-Id: <local-part@domain>

Content-Type: text/plain; charset=utf-8

Test

.

250 2.0.0 Ok: queued as 0EA2B53155

<...another mail transaction...>

quit