sendmail : mail not delivered

[Wolfgang S. Rupprecht]

Felipe Nunez <gatopardo at codetel.net.do> writes:
>   In other words, what have I done wrong ? 

If you want to send mail to the world you'll need a valid hostname
registered in DNS to send from.  Made up names like foo at localhost and
foo at bizet.sys.linux will be laughed at.

> How do I get to not using felipe at bizet.sys.linux as mi mail-address
> if just bizet.sys.linux is the name of my computer ?

Let's be serious, biznet.sys.linux is not a hostname that exists in
dns.  It is something you made up and set your hostname to.  That is
far from making it a valid hostname as far as the global domain name
system cares.

       $ host  biznet.sys.linux 
       Host biznet.sys.linux not found: 3(NXDOMAIN)

If you do want to send mail from your host you'll need to set your
hostname to the hostname associated with your IP (eg.
tdev224-251.codetel.net.do).  

Alternately you can also register a domain with a registrar and run
your own DNS.  That will require a bit more work (but isn't any harder
that setting up sendmail).  The problem you'll find is convincing your
ISP to set the correct hostname for the IP to hostname mapping
(sometimes called the rDNS).  Most will only do that for the higher
paying business accounts.  Without that mapping many hosts will still
decline your mail since the claimed hostname doesn't match the
hostname they see with a reverse DNS lookup.

-wolfgang
-- 
Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/