how to setup 'hostname fqdn' on a VPS

I recently bought a vps server with DirectAdmin installed on it. everything works fine except I can't send emails. the DirectAdmin's messaging system issued this notification:

Cannot find your hostname using the command '/bin/hostname --fqdn'. Please check this >command to ensure it works properly. If you get the error: hostname: Name or service not known

Check your /etc/resolv.conf and try setting it to use 127.0.0.1Unable to resolve your >hostname, . This will cause major issues when sending emai开发者_JS百科l.

Solution:

Create an A record for your hostname (.) in your DNS control panel. Point the hostname to >your server's main IP address. Also check /etc/hosts to ensure that the server ip is >correctly set.

my /etc/hosts contains this:

# Do not remove the following line, or various programs  
# that require network functionality will fail.  
127.0.0.1   localhost.localdomain localhost  
127.0.1.1   srvubu100.screweb.com   srvubu100      ::1     localhost ip6-localhost   ip6-loopback fe00::0 ip6-localnet   ff00::0 ip6-mcastprefix ff02::1   ip6-allnodes ff02::2 ip6-allrouters  

178.162.145.82      srv771.screweb.com  
178.162.145.82      srv771.bitcommand.com  
178.162.145.82      server1.novinhost.net  

You should set a hostname using the script /usr/local/directadmin/scripts/hostname.sh like this:

/usr/local/directadmin/scripts/hostname.sh host.yourdomain.com

Then you should edit your /etc/hosts file and leave it like this:

127.0.0.1 localhost.localdomain localhost
::1 localhost ip6-localhost

178.162.145.82 host.yourdomain.com

Then restart your exim (service exim restart) and it should work ok.