sendmail : 550 host unknown

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# 22  
Old 11-08-2001
step by step

that's the equipment. There's one single mail server for smtp. It's got a permanent Internet connection so it doesn't need to relay or forward mails to an outstanding mailsever. It should directly send the mails to the addressed domains.

My ISP set my two DNS Primary and secondary as usual.

that's the whole stuff.

I think your right about the dns problems. It isn't directly on dns resolving. but sendmail needs for sending to diffrent domains through itself as fqdn. The errors refers to, what isn't already defined in my dns, so sendmail couldn't find it, actually itself.
I dont know why but there are two dffrent cases about sendmail, I guess.

a) send mail to local domain. It don't look for, just localhost. No dns query!

b) ougoing mail to a differnt domain. Look for dns entrie on its own domain in dns - what it couldn't find, so the fatal error happend and breaks at host unknown!

Is my idea possible?

I don't know why sendmail needs to look for itself dns entrie to resolv itself.
# 23  
Old 11-08-2001
Your details are not sufficient. To solve the problem we need the complete details. For example: What is the FQDN of the machine where you are to trying to configure sendmail ?

Just this FQDN would be a great help ..... thanks
# 24  
Old 11-09-2001

fqdn is . but the domain is inactive. why is this a great help? anyway, any help is good!
# 25  
Old 11-09-2001
Because of this:

server# nslookup
> set type=ANY

** server can't find NXDOMAIN

So, it is not possible to send any mail to because it is not working in DNS properly as a FQDN.

What is the nameserver IP address for ? We will check this for MX records and other problems (if possible...)
# 26  
Old 11-12-2001
I set up the dns server, in a few hours should be all up! But why do I need this just for using smtp? For pop3 is clear! To resovl the server itself can be harcoded in host, isn't it?
# 27  
Old 11-12-2001
From the FAQS on Sunsolve:

Sendmail not working - host unknown.

From Mailer-Daemon ....

550 Host unknown (Name server:
no data known)

Mail gateway defined with DNS MX record.

nslookup works ok.

mail works if appears as a DNS A
type record.

Solution Summary

As there is no A type record to convert host name to address, you need
to tell sendmail to use DNS name lookup.

In /etc/mail/ in the Options section you need:

# Turn on the DNS name look up

This is included in versions of supplied with some patches
and included in Solaris 2.6
# 28  
Old 11-13-2001
deferred: connection refused by...

The dns is set up with the domain for my server but now I go this message by testing sendmail... does anyone know why sendmail defferes the message?


# /usr/lib/sendmail -v < /etc/hosts Connecting to via relay... Deferred: Connection refused by
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