"turn authentication on" -- a simple how to please!!

[Mel Flynn]

On Monday 07 September 2009 21:49:42 David Southwell wrote:

> My mailserver uses postfix and has a number of virtual domains. I am
> getting the following difficulties on delivery of legitimate emails to
> remote addresses failing with a request to tun authentication on.

Normally this shouldn't occur if you are relaying yourself. Remote mail 
servers should not have authentication on for outside mail. This would only be 
the case if the remote postmaster considers his mailserver private and does 
not want to receive mail from unknown people.

Therefore, this should only happen if your relay via your ISP using the 
relay_host parameter in main.cf.

> I am
> comparatively new to managing mailservers. Could someone please tell me
> what I need to do. My searches on google seem to give me long explanations
> of what is meant to happen but I cannot find simple instructions on how to
> fulfill the requirements!!
>
> dns1# fgrep abc /var/log/maillog
> Sep  7 17:01:59 dns1 postfix/smtp[86489]: 179BE34D41D:
> to=<competitions at bristolphoto.org.uk>,
> relay=mail.abc.org.uk[xxx.xxx.xxx.xxx]:25, delay=2.2, delays=2/0/0.15/0.03,
> dsn=5.0.0, status=bounced (host mail.abc.org.uk[xxx.xxx.xxx.xxx] said: 550
> Please turn authentication on (in reply to RCPT TO command))
> dns1#

Let us know what's not simple about this:
http://www.postfix.org/SASL_README.html#client_sasl
-- 
Mel