Local Mail a Fail

H

hruodr

I intentionally write here and not under "web and network services". ntentionally write without reading any documentation. Why?

Just after installing, I expect that doing a traditional command "mail root" or "mail user" does send a mail to the user, independently on how the networking is configured. Not only I, but a lot of programs expect it, for example vi and the many daemons.

Well, this is not working, although I never touched sendmail configuration.

It should be irrelevant to say that I have in rc.conf:

Code: 
hostname="fbsd"
local_unbound_enable="YES"

that I get with ping fbsd:

Code: 
ping fbsd
ping: cannot resolve fbsd: Host name lookup failure

That if I have in /etc/hosts a line "127.0.0.1 localhost fbsd", then the ping works, but sendmail not even start at boot and blocks it.

That mailq delivers:

Code: 
% mailq
                /var/spool/mqueue (5 requests)
-----Q-ID----- --Size-- -----Q-Time----- ------------Sender/Recipient-----------
w4L6c4vI000807        2 Mon May 21 06:38 <root@fbsd>
                 (host map: lookup (fbsd): deferred)
                                         <root@fbsd>

Why?! WHY THIS HORROR?!!
 
That was not enough. I had edit /etc/hosts to have there "127.0.0.1 localhost fbsd.domain.local".

My machine do have a name: localhost. Why "mail root" is not interpreted as "mail root@localhost" and sent to root?

Or does every machine have to be an inernet or local area net machine? The last is not egough: Since we have cool TLDs, there is now place for local FQDNs. Also not ".local" is reserved for local machines.

And why is fbsd not a FQDN consisting of only the TLD fbsd? I think, this is conform with the definition.
 
To be able to send and receive e-mails you need to have working DNS. The way that resolve work is configured in /etc/nsswitch.conf It first lookup for the local files like /etc/hosts then to DNS query if there's no match in the hosts.
 
With "fbsd.local" in /etc/hosts and /etc/rc.conf also works, but neither with "fbsd." nor with "fbsd". It seems, sendmail expects a name with at least two components, although one component should be a legal FQDN.

But it remains the original question. In man mail you read:

HISTORY
A mail command appeared in Version 1 AT&T UNIX. [...]
Click to expand...

At that time, there were no internet, no LANs, no UUCP, just machines with many users. mail was used to send messages to people in the same machine.

mail root means mail to the root of the machine. For that is not be necessary sendmail, MTAs, TLDs, FQDNs, DNSs, GTDZKs, ZZTPPOIs, XYZTQs, etc.
 
Can you quote a reliable source?

I suppose "localhost" is a FQDN. If I put "fbsd" or "fbsd." in /etc/hosts, it get resolved. The problem seems to lie in sendmail.

At the end of man hosts you read:

Host names may contain any printable character other than a field delimiter, newline, or comment character.
Click to expand...
 
Although I'm not sure there's an explicit statement somewhere that a TLD cannot identify a host, it's implied in many documents, e.g. RFC 1032 -- you will find more... Just accept that fact.

Btw, if you want to try to make your system accept a single TLD as an absolute domain name (which is the correct term for FQDN), you have to write it with a trailing dot, see RFC 1035, 5.1. Format. But don't be surprised if your implementation rejects this anyways.

About localhost, this is a TLD and at the same time expected to be queriable for A and AAAA records pointing to a local loopback interface, because it's special, as of RFC6761. It's not a FQDN as it isn't part of the global domain name tree.
 
I wrote above that sendmail does not treat "fbsd." (with a dot at the end) as a FQDN. I think, the following seems to be explicit:

A domain name (or often just a "domain") consists of one or more
components, separated by dots if more than one appears. In the case
of a top-level domain used by itself in an email address, a single
string is used without any dots.
[...]
The domain name, as described in this document and in RFC 1035 [2],
is the entire, fully-qualified name (often referred to as an "FQDN").
A domain name that is not in FQDN form is no more than a local alias.
Local aliases MUST NOT appear in any SMTP transaction.
Click to expand...

From 2.3.5 in https://tools.ietf.org/html/rfc5321#section-2.3.5

and

The following syntax will result in fewer problems with many
applications that use domain names (e.g., mail, TELNET).
<domain> ::= <subdomain> | " "
<subdomain> ::= <label> | <subdomain> "." <label>
[...]
Click to expand...

From 2.3.1 in https://tools.ietf.org/html/rfc1035
 
A top-level domain used in an email address requires this TLD to have an MX record defining the actual host that handles mail for that TLD. And again, while "fbsd." is syntactically correct as an absolute domain name, it still isn't a semantically correct FQDN, as it neither is an existing TLD nor one of the reserved ones (like localhost, example, ...).

But keep insisting if you want, I'll just stop responding now.
 
First there's nothing wrong with the sendmail.
The mail is mail user agent (MUA) that send e-mails using the mail transfer agent (MTA) in your case this is sendmail. When the MTA agent receive an email for user@domain it need to resolve the domain using the priority that is configured in /etc/nsswitch.conf by default this is hosts: files dns the file is /etc/hosts then if there's no match there the DNS query is send to the DNS server specified in /etc/resolv.conf nameserver
When you don't have your hostname registered in the DNS server or in the /etc/hosts file the MTA can't resolve the domain therefor the mails are hanging in the mail queue.
 
Zirias said:
it still isn't a semantically correct FQDN, as it neither is an existing TLD nor one of the reserved ones (like localhost, example, ...).
Click to expand...

Do you have a reliable source, that I cannot make a TLD in a local net exist, including running a DNS with a MX record to it?

And as I said: sendmail (in the default configuration in FreeBSD) does not treat localhost as FQDN.
 
VladiBG, this is not anymore a thema. My Domain is being resolved to 127.0.0.1 and sendmail is delivering local mails. But sendmail demands that the FQDN have two labels, and I find this strange.
 
No there's no such demand by sendmail. The only requirement is to be resolved. You can add only fbsd in your hosts file and it will work.
Code: 
::1          localhost fbsd localhost.my.domain
127.0.0.1    localhost fbsd localhost.my.domain
 
Did you try it? I tried again. I put fbsd in /etc/hosts and /etc/rc.conf again.

At every invocation of sendmail, even at boot (and indirectly by calling mail), I get the message:

Code: 
fbsd sendmail[802]: My unqualified host name (localhost) unknown; sleeping for retry

But it continues after a while. And mails are delivered with the "localhost" domain. It ignores the "fbsd" FQDN and uses localhost, what I would even prefer.

This is only because of the messages and delay unusable. Perhaps it can be fixed configuring sendmail carefully, but for that one needs (at least I) a lot of time.
 
hruodr You come here looking for help, then put test questions at us as if we are the ones with a problem. I suggest you listen and learn first from people far more knowledgeable than you. Solve your problem. Then look for answers to your questions about sources.
 
Yes i tried in a vm and it's working as expected.. FQDN is not required.
 

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At least you do not get the delay. But it seems that it takes localhost.my.domain as domain for email.

If I send myself a mail now, mail root, it appears as coming from <root@fbsd.local> and has Message-Id like <201805211201.w4LC1bpd001083@fbsd.local>.

It seems you will not get a mail from <root@btest>, perhaps also not from <root@localhost>, but from <root@localhost.my.domain>. I did manage to get it from <root@localhost>, but with the delays.

And it is strange why you get a different experience. We are using the same version of sendmail, and perhaps of FreeBSD (11.1).

Perhaps there is no way around than carefully configuring sendmail, but this is the tragedy: something so important like local mail should be in my opinion not so sensible to the configuration of things which are irrelevant to it (like DNS).
 
@gkontos
Look at the top of the log from=<root@btest>
i've tested both configuration with and without local_unbound, both works.

ohh sorry my bad, the screenshot not include the past log here the above that.
1526905216081.png
 
Zirias, perhaps you did not get the message, perhaps you do not want to understand it: local mail should work out of the box, and not stop working due to things that are irrelevant to it.
 
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