[gentoo-user] Help with local mail, please

[gentoo-user] Help with local mail, please

[Peter Humphrey]

Hello list,

For years, I've been using postfix to accept mail from LAN hosts, and from the 
Internet via my ISP. This has never worked as I want it - it's just so complex 
to set up and understand. Well, it is for a bear of little brain like me.

Can someone tell me how to make postfix accept all mail addressed to any host 
or user on the LAN - and not forward any mail to anywhere at all? It's running 
on a single-homed host on the LAN, and all other hosts are also single homed. 
Any of four hosts can originate mail, and I have fetchmail running on the same 
host to collect POP3 mail from my ISP. Dovecot serves IMAP4 to KMail clients 
on the LAN.

At present, postfix is insisting on forwarding mail addressed to root on a LAN 
machine, but it's supposed to be acting on behalf of that machine. Two other 
hosts' mails never show up anywhere.

Or perhaps there's a more suitable MTA out there?

-- 
Regards,
Peter.

Re: [gentoo-user] Help with local mail, please

[Arve Barsnes]

On Tue, 13 Feb 2024 at 16:52, Peter Humphrey <peter@prh.myzen.co.uk> wrote:
> For years, I've been using postfix to accept mail from LAN hosts, and from the
> Internet via my ISP. This has never worked as I want it - it's just so complex
> to set up and understand. Well, it is for a bear of little brain like me.
>
> Can someone tell me how to make postfix accept all mail addressed to any host
> or user on the LAN - and not forward any mail to anywhere at all? It's running
> on a single-homed host on the LAN, and all other hosts are also single homed.
> Any of four hosts can originate mail, and I have fetchmail running on the same
> host to collect POP3 mail from my ISP. Dovecot serves IMAP4 to KMail clients
> on the LAN.
>
> At present, postfix is insisting on forwarding mail addressed to root on a LAN
> machine, but it's supposed to be acting on behalf of that machine. Two other
> hosts' mails never show up anywhere.

I'm not sure I quite understood where you're having problems, but I
have a machine that accepts mail from the LAN through postfix, so I'll
show some of my setup. Replace any <> with your hostnames.

On the LAN machine I don't have postfix, I only send mail directly to
the machine with 'sendmail', but I found that I have in
/etc/mail/mailertable:
192.168. smtp:<mail machine hostname>
<mail machine hostname> esmtp:<mail machine hostname>
And in /etc/mail/local-host-names I have set <mail machine hostname> -
maybe that does something, but I send mail directly with sendmail
either way.

On the postfix machine I have in /etc/postfix/aliases:
root:           arve
This should make all mail to root be delivered to me. It also contains
a bunch of aliases that I'm not sure if is necessary:
arve@<hostname>             arve
arve@<hostname>.lan         arve
arve@<hostname>.localdomain arve
arve@<other machine hostname>.lan              arve

In /etc/postfix/main.cf there is this, and I assume at least some of
this makes this all work:
myhostname = <hostname>.lan
inet_interfaces = $myhostname, localhost
mydestination = $myhostname, localhost.$mydomain, localhost, <hostname>
mynetworks = 192.168.0.0/24, 127.0.0.0/8

Regards,
Arve

Re: [gentoo-user] Help with local mail, please

[Peter Humphrey]

On Tuesday, 13 February 2024 17:20:40 GMT Arve Barsnes wrote:

> I'm not sure I quite understood where you're having problems, but I
> have a machine that accepts mail from the LAN through postfix, so I'll
> show some of my setup. Replace any <> with your hostnames.
> On the LAN machine I don't have postfix, I only send mail directly to
> the machine with 'sendmail', but I found that I have in
> /etc/mail/mailertable:
> 192.168. smtp:<mail machine hostname>
> <mail machine hostname> esmtp:<mail machine hostname>
> And in /etc/mail/local-host-names I have set <mail machine hostname> -
> maybe that does something, but I send mail directly with sendmail
> either way.

I think those entries must be for sendmail.

> On the postfix machine I have in /etc/postfix/aliases:
> root:           arve
> This should make all mail to root be delivered to me.

Yes, I have root: prh, but postfix still tries to forward mail for 
root@<otherhost> to <otherhost> instead of hanging on to it.

> It also contains a bunch of aliases that I'm not sure if is necessary:
> arve@<hostname>             arve
> arve@<hostname>.lan         arve
> arve@<hostname>.localdomain arve
> arve@<other machine hostname>.lan              arve

I hadn't thought of doing that. When I tried it, postfix complained "Names must 
be local" and wouldn't accept my root@<host> entries.

> In /etc/postfix/main.cf there is this, and I assume at least some of
> this makes this all work:
> myhostname = <hostname>.lan
> inet_interfaces = $myhostname, localhost
> mydestination = $myhostname, localhost.$mydomain, localhost, <hostname>

Isn't <hostname> the same as $myhostname?

> mynetworks = 192.168.0.0/24, 127.0.0.0/8

I'll try setting mynetworks and see what happens.

Thanks, Arve.

-- 
Regards,
Peter.

Re: [gentoo-user] Help with local mail, please

[Arve Barsnes]

On Tue, 13 Feb 2024 at 23:11, Peter Humphrey <peter@prh.myzen.co.uk> wrote:
> On Tuesday, 13 February 2024 17:20:40 GMT Arve Barsnes wrote:
> I think those entries must be for sendmail.

Yes, that machine has sendmail from mail-mta/opensmtpd, not postfix,
not sure it matters.

> > In /etc/postfix/main.cf there is this, and I assume at least some of
> > this makes this all work:
> > myhostname = <hostname>.lan
> > inet_interfaces = $myhostname, localhost
> > mydestination = $myhostname, localhost.$mydomain, localhost, <hostname>
>
> Isn't <hostname> the same as $myhostname?

No, $myhostname is <hostname>.lan

Like you I've had some trouble in the past, so a lot of this is from
trying and failing, but it works as I want it now, so I'm happy-ish.

Regards,
Arve

Re: [gentoo-user] Help with local mail, please

[J. Roeleveld]

On Tuesday, February 13, 2024 4:52:03 PM CET Peter Humphrey wrote:
> Hello list,
> 
> For years, I've been using postfix to accept mail from LAN hosts, and from
> the Internet via my ISP. This has never worked as I want it - it's just so
> complex to set up and understand. Well, it is for a bear of little brain
> like me.
> 
> Can someone tell me how to make postfix accept all mail addressed to any
> host or user on the LAN - and not forward any mail to anywhere at all? It's
> running on a single-homed host on the LAN, and all other hosts are also
> single homed. Any of four hosts can originate mail, and I have fetchmail
> running on the same host to collect POP3 mail from my ISP. Dovecot serves
> IMAP4 to KMail clients on the LAN.
> 
> At present, postfix is insisting on forwarding mail addressed to root on a
> LAN machine, but it's supposed to be acting on behalf of that machine. Two
> other hosts' mails never show up anywhere.
> 
> Or perhaps there's a more suitable MTA out there?

I've been using postfix for longer than I can remember.
The config entries I changed from default are:

--- main.cf ---
myhostname = <hostname.TLD>
mydomain = <TLD>
myorigin = <TLD>
mynetworks = <full list of local networks, ex. :  192.168.0.0/24, 
192.168.1.0/24>
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, 
reject_unauth_destination
-------

Also, are all emails sent to "mydomain" or do you have additional domains 
configured?
If the latter, did you set "virtual_alias_domains = hash:/etc/postfix/
virtual_domains"
Include all virtual domains the file and converted the file to a .db ?

--
Joost

Re: [gentoo-user] Help with local mail, please

[Peter Humphrey]

On Wednesday, 14 February 2024 11:35:18 GMT J. Roeleveld wrote:

> I've been using postfix for longer than I can remember.
> The config entries I changed from default are:
> 
> --- main.cf ---
> myhostname = <hostname.TLD>
> mydomain = <TLD>
> myorigin = <TLD>
> mynetworks = <full list of local networks, ex. :  192.168.0.0/24,
> 192.168.1.0/24>

That's helpful - thanks Joost.

> smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated,
> reject_unauth_destination

No relaying here; all outgoing mail goes to my ISP.

> Also, are all emails sent to "mydomain" or do you have additional domains
> configured?
> If the latter, did you set "virtual_alias_domains = hash:/etc/postfix/
> virtual_domains"
> Include all virtual domains the file and converted the file to a .db ?

Just the one "mydomain"

-- 
Regards,
Peter.

Re: [gentoo-user] Help with local mail, please

[J. Roeleveld]

On Friday, February 16, 2024 6:19:25 AM CET Peter Humphrey wrote:
> On Wednesday, 14 February 2024 11:35:18 GMT J. Roeleveld wrote:
> > I've been using postfix for longer than I can remember.
> > The config entries I changed from default are:
> > 
> > --- main.cf ---
> > myhostname = <hostname.TLD>
> > mydomain = <TLD>
> > myorigin = <TLD>
> > mynetworks = <full list of local networks, ex. :  192.168.0.0/24,
> > 192.168.1.0/24>
> 
> That's helpful - thanks Joost.

You're welcome. Was this enough to get it working?

> > smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated,
> > reject_unauth_destination
> 
> No relaying here; all outgoing mail goes to my ISP.

If your mailserver (postfix) is sending emails to your ISP, that is (from the 
viewpoint of postfix) relaying by definition.

> > Also, are all emails sent to "mydomain" or do you have additional domains
> > configured?
> > If the latter, did you set "virtual_alias_domains = hash:/etc/postfix/
> > virtual_domains"
> > Include all virtual domains the file and converted the file to a .db ?
> 
> Just the one "mydomain"

If you have only 1 domain, keep that "virtual_alias_domains" empty.

--
Joost

Re: [gentoo-user] Help with local mail, please

[Peter Humphrey]

On Friday, 16 February 2024 12:30:48 GMT J. Roeleveld wrote:
> On Friday, February 16, 2024 6:19:25 AM CET Peter Humphrey wrote:
> > On Wednesday, 14 February 2024 11:35:18 GMT J. Roeleveld wrote:
> > > I've been using postfix for longer than I can remember.
> > > The config entries I changed from default are:
> > > 
> > > --- main.cf ---
> > > myhostname = <hostname.TLD>
> > > mydomain = <TLD>
> > > myorigin = <TLD>
> > > mynetworks = <full list of local networks, ex. :  192.168.0.0/24,
> > > 192.168.1.0/24>
> > 
> > That's helpful - thanks Joost.
> 
> You're welcome. Was this enough to get it working?

I forgot to add that my system was already almost identical to yours, so I 
don't know whether to say yes or no.   :)

> > > smtpd_relay_restrictions = permit_mynetworks, 
permit_sasl_authenticated, reject_unauth_destination
> > 
> > No relaying here; all outgoing mail goes to my ISP.
> 
> If your mailserver (postfix) is sending emails to your ISP, that is (from
> the viewpoint of postfix) relaying by definition.

Er... outgoing mail doens't go through postfix at all; it goes direct from my 
KMail client to my ISP.

> > > Also, are all emails sent to "mydomain" or do you have additional
> > > domains configured?
> > > If the latter, did you set "virtual_alias_domains = hash:/etc/postfix/
> > > virtual_domains"
> > > Include all virtual domains the file and converted the file to a .db ?
> > 
> > Just the one "mydomain"

...so no need to set any virtual domains.

> If you have only 1 domain, keep that "virtual_alias_domains" empty.

No such setting in my main.cf so I assume it's empty.

Anyway, I looked at some of those mails that postfix was trying to forward, and 
they were old and unimportant, so I purged them.

Let's see what other problems I've made for myself...  :)

-- 
Regards,
Peter.