Re: Listening on port 25 to receive mail

["Jeremy C. Reed" <reed%reedmedia.net@localhost>]

On Fri, 5 Dec 2014, Rocky Hotas wrote:

> I tried to send an e-mail from a host in a LAN to another host in the 
> *same* LAN which runs NetBSD. But the connection was refused because 
> the NetBSD host is not listening on port 25.
> How could I make it possible?

Your subject says to receive mail and your need is to "relay" mail. Both 
can be done by default with already installed software.

/etc/rc.d/postfix rcvar

Set "postfix=YES" like in your /etc/rc.conf (or in 
/etc/rc.conf.d/postfix).

Make sure you have the original /etc/mailer.conf and then run the start 
script:

/etc/rc.d/postfix start

This may rebuild your mail aliases database and start the Postfix mail 
system, which includes, by default, the postfix master, pickup, and qmgr 
daemons. But none of these offer the SMTP listening service. Edit the 
/etc/postfix/master.cf file and you can uncomment the first "#smtp" line 
by removing the "#" hash mark. Tell postfix to reload with:

postfix reload 
(or /etc/rc.d/postfix reload)

Then you should see the *.25 port listening with netstat. (No smtpd 
daemon is started yet; it will be started when needed. Other postfix 
processes may start too, like smtp, proxymap, cleanup, trivial-rewrite, 
and/or bounce,)

You may need to study postfix documentation to learn more, but by 
default it should relay for networks as seen by running:

postconf mynetworks

You don't need official Sendmail sendmail from packages. But I do have 
some comments below:

> First I installed sendmail from pkg. Then, following the instructions 
> at the end of the installation, I forced the symbolic link
> 
> /usr/sbin/sendmail (which initially pointed to /usr/sbin/mailwrapper)
> 
> to point to /usr/pkg/libexec/sendmail/sendmail.

You don't need to createthe symlink. When installing the package, there 
should be a message about the mailwrapper and mailer.conf. You should 
have a /usr/pkg/share/examples/sendmail/mailer.conf that 
you can copy to /etc/mailer.conf (instead of doing symlinks for all). 
(Be sure to backup original first).

> Next, I put the line
> 
> sendmail=YES
> 
> in /etc/rc.conf. However, after rebooting, in the output of
> 
> netstat -an -f inet |grep LISTEN
> 
> there was anything about port 25.

I assume you have no /etc/rc.d/ script for sendmail and your startup 
configuration doesn't know to look at scripts under /usr/pkg/etc/rc.d/ 
(see rc_directories setting) --- and also probably sendmail rc.d script 
wasn't copied there. There are more simple steps for this, but I will 
stop here.  Because maybe the postfix ideas above will work for you 
quickly.