mailer problems

[Maurice Peterse]

I have several systems.
2 of them can't mail to system x
other systems CAN mail to system x

what can i check?

[RikTytgat]

Hi,

I would check whether hostnames are resolved properly.

Does 'nslookup ' work?

If not, you have a lot of options:
- Do you have a DNS server at your site? Then use it by adding the line
nameserver ip_of_nameserver
to /etc/resolv.conf
- Add the hosts you want to mail to to your /etc/hosts file in following format
ip_address FQDN alias alias ...
where FQDN is the Fully Qualified Domain Name (mymailhost.mydomain.com). Check the contents of /etc/nsswitch.conf. This shoul contain a line looking like:
hosts:files [NOTFOUND=continue] dns
to tell the resolver to first try to resolve using /etc/hosts, and then using the DNS server.

I hope this can solve your problem.
Rik.

[Maurice Peterse]

I do have NDS
/etc/mail/service.switch didn't exist, now it does
/etc/resolv is ok

any more options?

[RikTytgat]

Hi,

What is the ouptut of the command

nslookup

where is the hostname of the server you wish to mail to?

Does this return the correct IP address?

Bye,
Rik

[Maurice Peterse]

yes, exactly the right ip address

[Julian Sinclair_1]

you might also want your sendmail setup on the machines which are not sending mail.
send a mail from a machine which is not working and check the syslog for the sendmail entries. Compare this with the entries entered for a mail that is sent correctly. This should at least give you an idea where the is mail is being rejected.

What MUA are you using and what version of sendmail ?

[Maurice Peterse]

Jul 19 10:04:51 zzzz sendmail[9332]: KAA09332: Ruleset check_mail () rejection: 418 ... invalid host name

Jul 19 10:09:33 zzzz sendmail[9450]: KAA09450: from=, size=0, cla
ss=0, pri=0, nrcpts=0, proto=ESMTP, relay=[199.81.70.13] (may be forged)

this is in /var/adm/syslog/mail.log on the receiving system....

[Anthony deRito]

Run sendmail in address testing mode on each machine and it will print what it can find as the address of the local machine including its domain name.

sendmail -d0.1 -bt < /dev/null

Verify the names are correct and that you can use nslookup for each name from each machine.