Re: [gentoo-user] Setting up SMTP relay

[Alex Schuster <wonko@wonkology.org>]

kashani writes:

> On 1/22/2011 1:34 PM, Alex Schuster wrote:

> I handle it with Postfix. Dovecot is only imap and won't accept main 
> directly.

Whoops.

> 1. install postfix with USE sasl or devecot-sasl, I don't believe it 
> matters which. Add the following lines to the bottom of 
> /etc/postfix/main.cf and fill in your hostname, domain, etc as needed.
> 
> # local settings
> myhostname = host.domain.com
> mydomain = domain.com
> myorigin = $myhostname
> inet_interfaces = all
> mydestination = $myhostname, localhost.$mydomain, localhost
> mynetworks_style = subnet
> mynetworks = 127.0.0.0/8 10.19.20.0/24

I left most items commented out as they are the same as the default, I
only had to set mydomain, although dnsdomainname and hostname -d both
return wonkology.org.

> 2. run sudo newaliases
> 	Postfix bitches if the /etc/mail/aliases.db doesn't exist and will hang 
> on start.
> 
> 3. Verify postfix works, isn't complaining in the logs, etc.
> 	Make sure it's up and running. That you can telnet to port 25 from 
> another machine and even send to a local user on your machine.

Looks good!

> 4. Add the user/pass stuff to the bottom of /etc/postfix/main.cf
> 
> # relay host and credentials
> relayhost = [my.external.relayhost.com]
> smtp_sasl_auth_enable = yes
> smtp_sasl_password_maps = hash:/etc/postfix/sasl.passwd
> smtp_sasl_mechanism_filter = digest-md5
> smtp_sasl_security_options = noanonymous

I need TLS authentication, and found what I need in a howto:
smtp_sasl_tls_security_level = may
And I removed smtp_sasl_mechanism_filter.

> 5. Once you're this far it's time to test all the way through.
> 
> make sure you can send from the localhost machine
> sendmail -v some@address.com
> .
> 
> Once you're sure that works test from another machine on the network. 
> Ideally it should just work if you've done all the steps.

Relaying does not work yet, I get a "Relay access denied (in reply to
RCPT TO command)" error. But my initial goal is reached, I can send mail
to {root,wonko}@wonkology.org. That's all I wanted.

Many many thanks kashani! Your howto is much more than I expected, it is
much appreciated. I realize that postfix is not too complicated, so I
will play more with it when I have some spare time.

	Wonko