This thread discusses the Content article: PostFix with DoveCot Install for CentOS-4 (WBEL-4 / TaoLinux-4 / RHEL-4) Part 1

My ISP just cut off port 25 outoing on me so I need to smart host to them and authenticate.

Is there a guide to make postfix do this?

I am confused between smtp_sasl_XXXXX and smtpd_sasl_XXXXX that you have in your guide

I tried this so far:

// First check for the right name to use
nslookup esmtp.unwired.com.au
Server: 220.101.191.16
Address: 220.101.191.16#53

Non-authoritative answer:
esmtp.unwired.com.au canonical name = smtp-unwired.bluetie.com.
Name: smtp-unwired.bluetie.com
Address: 206.65.163.242


// Enabling smtp authentication

Create a text file mapping which name/password should be used for each given outbound destination:
This is the usernameassword you would enter in the advance options of smtp server in a mail client to send email other than the ISP's

echo smtp-unwired.bluetie.com usernameassword > relay_password

[root@mail ~]# cat relay_password
smtp-unwired.bluetie.com usernameassword

// Create a postfix lookup table and test it is OK
[root@mail ~]# postmap relay_password
[root@mail ~]# postmap -q smtp-unwired.bluetie.com relay_password
usernameassword


// Make postfix use the above

postconf -e smtp_sasl_password_maps=hash:/etc/postfix/relay_password
postconf -e smtp_sasl_auth_enable=yes

Restart postfix:

postfix reload

// Troubleshooting

After sending a test message, check the Log Files for the error:
(Authentication failed: cannot SASL authenticate to server ...: no mechanism available)

You can fix this problem by tweaking the auth mechanisms that postfix is willing to use. First check what auth mechanism postfix is configured to use - by default, you will see:

$ postconf smtp_sasl_security_options
smtp_sasl_security_options = noplaintext, noanonymous

Since noplaintext is present, postfix will refuse to use a mechanism that sendspasswords in the clear. If your upstream relay host only supports PLAIN or LOGIN mechanisms (both of which send password in the clear), you have to remove noplaintext from smtp_sasl_security_options:

$ postconf -e smtp_sasl_security_options=noanonymous
$ postfix reload