Postfix as a smarthost SMTP Server

Keitex · 12-10-2010, 08:48 AM

Hi, I am trying to setup Postfix on Ubuntu to run as a smarthost for my Exchange 2010 server and a couple of other Exchange 2003 servers.

I followed the guide and can send mail from the server but I cannot get the Exchange to relay the mail Gets stuck in the queue. I get the following error:

"421 4.4.2. Connection dropped due to TimedOut. Attempted failover to alternative host, but that did not succeed"

What should I use as a username and password for the Basic Authentification? Would it be user@mydomain.com or just user?

Here is my config file

Code:

# See /usr/share/postfix/main.cf.dist for a commented, more complete version


# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = 80-93-162-207.rdns.mkdc.co.uk
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# TLS parameters
smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = mars, localhost.localdomain, , localhost, sendmail.avecsysonline.com
mailbox_size_limit = 0
recipient_delimiter = @
myorigin = /etc/mailname
inet_protocols = all
smtpd_recipient_restrictions = permit_mynetworks permit_inet_interfaces permit_sasl_authenticated
smtpd_tls_security_level = none
mydomain = sendmail.avecsysonline.com
mynetworks = 127.0.0.0/8 80.93.162.192/26 [::1]/128 [fe80::%eth0]/64
smtpd_delay_reject = no

Thank you

Noway2 · 12-11-2010, 05:42 AM

On which server are you getting this error, the exchange or postfix? The error that you describe sounds like something is not able to communicate properly, perhaps establish a connection to the next desired host. Your postfix server logs may provide a clue as to what is happening. What error message is showing up in there?

I am also not sure I am entirely following your post. Please clarify what you mean by: "I followed the guide", "can send mail from the server", and "cannot get the Exchange to relay the mail". What guide did you follow? Is your postfix server working as a stand-alone server for send and receive mail? And with regards to the exchange server are you trying to relay TO or FROM the exchange server with regards to postfix.

I am also not understanding what you mean by what you should use for basic authentication? Postfix can authenticate users in various ways such as allowing all users in your domain, using SASL authentication (via Dovecot or Cyrus), including support for virtual users. What you have to enter would depend on how you have configured your system, including the sender restrictions. Per the file you have posted you don't appear to be using SASL, consequently, I suspect that if the mail appears to be originating from within your network, which you specified with the network ranges, Postfix will accept and try to deliver the mail. If the mail is for one of your domains, it will try to locally deliver it. If it is not, it will connect to the next up stream host to pass the message on.

Reuti · 12-11-2010, 03:27 PM

Do you have any output in any of the /var/log/mail* or /var/log/firewall regarding this issue? Maybe the firewall blocks access to this machine at all.