[TriLUG] Postfix Woes

[Aaron Bockover]

I have these three base settings, but still to no avail. Also the server
that I am running on is not behind Earthlink's network. It is wide open
on another network, and 25 is not filtered at all. But behind my ISP
(Earthlink), they do filter access to 25, allowing only direct SMTP
connections to their SMTP server. So to get around that from my house, I
just forwarded traffic from 26 to 25 on the server that sits outside the
Earthlink network.

Thanks for the tips, I'll double check my config though.

--Aaron

On Wed, 2005-04-13 at 02:09 -0400, Michael Hrivnak wrote:
> The only settings I had to change to get that functionality are these:
> 
> mydomain = somewhere.com
> mydestination = $mydomain (and possibly other things)
> 
> More comments are intermingled.  Also, there are postfix wizards on this list 
> that may have more to say on the matter.
> 
> On Wednesday 13 April 2005 01:27 am, Aaron Bockover wrote:
> > Okay, having never worked with Postfix or any email system before, other
> > than web-based user administration on my shared hosting systems, diving
> > head first into the world of email systems is slightly overwhelming,
> > considering the time restrictions I am under.
> >
> > I am right now just working with Postfix. I have the server set up, and
> > it is delivering mail into user Maildirs (/home/user/Maildir). I can
> > connect to the SMTP server from localhost and send a message without a
> > problem. I can connect via telnet from my desktop (which is on a
> > completely separate network), actually through port 26 (set up a
> > iptables rule on the server to forward 26->25, thanks Earthlink!) and
> > send a message.
> 
> Make sure that such a remote connection can only send a message to your local 
> domain.  And are you saying that inbound port 25 is filtered?
> 
> >
> > The problem is sending a message through Earthlink's SMTP server, as set
> > up in Evolution. My Postfix server is denying the message relayed from
> > the Earthlink SMTP server.
> 
> I'm guessing that's because earthlink's smtp server is trying to connect to 
> port 25 on your machine, which apparently they filter.  Their relay has no 
> way of knowing that your machine is running smtp on a non-standard port.  The 
> only way around this that I see is to have an smtp server somewhere else on 
> the net to which inbound port 25 is not filtered.  That smtp server is setup 
> simply as a relay for your domain, but not the destination.  Then you could 
> use the transport map to specify that any connections to your destination 
> machine occur on a different port.  You'd need an entry 
> in /etc/postfix/transport such as:
> 
> somewhere.com     smtp:[somewhere.com]:26
> 
> Any time that file is changed, you need to run:
> 
> postmap /etc/postfix/transport
> 
> And, of course, in your MX record you specify that remote machine as the 
> primary email server for your domain.
> 
> 
> 
> >
> > I was thinking that the "mynetworks" and "mynetworks_style" settings in
> > main.cf have something to do with this?
> >
> > Does anyone have a config that I can work with that handles the
> > following goals:
> >
> > 1. Accept incoming SMTP connections from anywhere and messages bound for
> > the local server
> > 2. Do not relay messages from any other host except the local server
> > (and other hosts manually specified) to remote SMTP servers
> 
> mynetworks_style = host
> 
> >
> > If I can get mail delivered from any SMTP server to mine, then I think I
> > can really get going with Postfix, and move on to virtual domains and
> > users, and then getting Courier-IMAP set up to read the Maildirs.
> >
> > I'd also appreciate any other Postfix/Courier-IMAP related
> > tips/tricks/articles that anyone may have to share! Email is the only
> > system I'm not too familiar with! It'd be more fun if I had more
> > time :-/
> >
> > Thanks!
> >
> > Aaron Bockover