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 => firstname.lastname@example.org R=smarthost T=remote_smtp_smarthost H=email32.luxsci.com [ 22.214.171.124] 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"
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 ** email@example.com R=smarthost T=remote_smtp_smarthost: SMTP error from remote mail server after RCPT TO:<firstname.lastname@example.org >: host secure-email-32.luxsci.com [126.96.36.199]: 550 5.7.1 <email@example.com>... Relaying denied. Proper authentication required.