Choosing the right hostname

Dimitris sehh at
Fri Feb 7 08:50:59 GMT 2003

On Thu, 6 Feb 2003 11:47:04 -0000 "Andrew" <andrew.hodgson at> wrote:

> <<< 553 5.1.8 <root at>... Domain of sender
> address root at does not exist

I think you have a problem in your dns server resolving the address

dig shows:

;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
; IN   A

Notice the QUERY 1, ANSWER 0 (no answer).

Sendmail is doing a spam check, and the domain of the sender can not be resolved
as an IP address at all via an authoritative DNS server.

Sendmail does NOT look at your /etc/hosts. If you want to forward the daily updates
from your fbsd box to your real email address then you'll have to force sendmail
to use a real domain name, or something that resolves at your local DNS server. If
you don't run your own dns server then you can use and register a dynamic domain!

I registered '' at, which now resolves back to my
system, then i changed the sendmail configuration to force it to use that domain
instead of my 'server' domain:
# file containing names of hosts for which we receive email
Fw-o /etc/mail/local-host-names
# my official domain name
# ... define this only if sendmail cannot automatically determine your domain

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