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I'm trying to debug a problem with email sending on my home machine, possibly a router related problem. This is on Debian squeeze with Exim 4.72-6+squeeze3 (the default Exim 4 Debian package for this release).

I'm getting a Relaying denied. Proper authentication required error.

A reasonable first step is to determine what port my Exim 4 client is currently attempting to use. However, this seems to be surprisingly difficult to find out.

The Debian documentation tells me that the Debian Exim tries to use TLS if available, but I don't know how to confirm that either. Here is an example from my Exim client log (/var/log/exim4/mainlog), when mail sending was still working.

2013-04-28 15:04:30 1UWNzx-00084Y-EO => foo@bar.com R=smarthost T=remote_smtp_smarthost H=email32.luxsci.com [
64.39.7.160] X=TLS1.0:RSA_AES_256_CBC_SHA1:32 DN="serialNumber=OeuJg-G-8alU-6KqWL5z-WwlWFVKQgwj,C=US,ST=Massachusetts,L=Dedham,O=Lux    
Scientiae,OU=Secure Services,CN=*.luxsci.com"

Does the TLS1 mean TLS is being used, or is it just a meaningless string? Assuming it is using TLS, then that suggests that port 465 is used, since that is apparently the default. But how can I confirm any of this?

Here is a version of the currently failing mail sending.

2013-05-05 22:11:28 1UZ0OM-0003SM-6Z ** faheem@faheem.info R=smarthost T=remote_smtp_smarthost: SMTP error from remote mail server after RCPT    
TO:<faheem@faheem.info
>: host secure-email-32.luxsci.com [64.39.7.160]: 550 5.7.1 <faheem@faheem.info>... Relaying denied. Proper authentication required.
Faheem Mitha
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2 Answers2

1

You may want to add a log line showing the port that is actually used during this very connection. Something like (not sure if you really need the condition)

warn    condition       = yes
        log_message     = Port: $received_port

in the beginning of your check_helo acl.

Hardy
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0

It seems that
1) your exim sends outgoing email via smart host
2) the smart host refuses to relay (accept to send send further) without SMTP AUTH

Your Exim (by default) should use port 25.
secure-email-32.luxsci.com offers STARTTLS extension of ESMTP protocol => your MTA/exim can turn unencrypted SMTP connection into encrypted one (the same TCP connection).
secure-email-32.luxsci.com offers only "plain text" methods of SMTP AUTH (LOGIN and PLAIN) so your exim SHOULD use them after STARTTLS command

AnFi
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