> > <snip>
> > However I observe strange behaviour of sendmail.
> > When flam is not connected to Internet (only to LAN) then
> > it can not redirect mail:
> >
> > j1I0T7FM013366      419 Fri Feb 18 03:29 <root@flam.gado>
> >                  (Deferred: Name server: chup.gado.: host name lookup
> > failure) dina@chup
> > j1I0T93I013347     2351 Fri Feb 18 03:29 <root@flam.gado>
> >                  (Deferred: Name server: chup.gado.: host name lookup
> > failure) dina@chup
> >
> > maillog contains:
> >
> > Feb 18 10:06:41 flam sendmail[15915]: j1I0T93I013347: to=dina@chup,
> > ctladdr=<root@flam.gado> (0/0), delay=06:37:32, xdelay=00:00:00,
> > mailer=esmtp, pri=35852690, relay=chup.gado., dsn=4.0.0, stat=Deferred:
> > Name server: chup.gado.: host name lookup failure
> >
> > Notice trailing dot in the name chup.gado.
> >
> > When I rise Internet connection on flam.gado via GPRS then
> > mail is successfully sent.
> 
> I think your problem is that you use external DNS servers to look up your 
> local hostnames (chup.gado in this case). When the Internet connection goes 
> down, your system is not able to find the IP address for chup.gado. It's easy 
> to solve this by editing your /etc/hosts file. Add a new line there 
> containing the IP address and hostname for the machine you want to look up 
> (chup.gado).

No, it is not the answer.
Actually external DNSes do not know anything about chup.gado
chup.gado is written in /etc/hosts

Also (remember strange trailing dot) I've also added chup. and chup.gado. to /etc/hosts

I recall that recently in -current new version of /etc/hosts was committed
and now it contains localhost. as well as localhost
Why?  Probably it is somehow related to my problem.