[Tech] Postfix: " Name or service not known"

[Aldo Podavini]

Sto uscendo pazzo !!

Ho installato postfix su una macchina, come tante altre volte, e non c'è 
verso di convincerlo a fare il relay a nesusn indirizzo esterno.
In maillog trovo:

Jul 29 18:44:41 hermes2 postfix/smtp[3450]: warning: no MX host for 
ldvsrl.it has a valid A record
Jul 29 18:44:41 hermes2 postfix/smtp[3450]: A2C4434EE73: 
to=<pippo@topolinia.it>, relay=none, delay=0, status=bounced 
([mail.topolinia.it]: Name or service not known)

Inutile dirvi che topolinia.it ha il suo record MX correttamente 
impostato, e che comunque il problema si propone con qualsiasi indirizzo.
postfix check non restituisce errori, in /var/spool/postfix/lib ho tutte 
(credo) le librerie necessarie:
-rwxr-xr-x   1 root root  251252 29 lug 18:53 libdb2.so.3
-rwxr-xr-x   1 root root   30156 29 lug 18:54 libnss1_compat-2.3.4.so
-rwxr-xr-x   1 root root   13736 29 lug 18:54 libnss1_dns-2.3.4.so
-rwxr-xr-x   1 root root   34264 29 lug 18:54 libnss1_files-2.3.4.so
-rwxr-xr-x   1 root root   31228 29 lug 18:54 libnss1_nis-2.3.4.so
-rwxr-xr-x   1 root root   34532 29 lug 18:54 libnss_compat-2.3.4.so
lrwxrwxrwx   1 root root      22 29 lug 18:57 libnss_compat.so.1 -> 
libnss_compat-2.3.4.so
-rwxr-xr-x   1 root root   17844 29 lug 18:54 libnss_dns-2.3.4.so
lrwxrwxrwx   1 root root      19 29 lug 18:56 libnss_dns.so.1 -> 
libnss_dns-2.3.4.so
-rwxr-xr-x   1 root root   38360 29 lug 18:54 libnss_files-2.3.4.so
lrwxrwxrwx   1 root root      21 29 lug 18:56 libnss_files.so.1 -> 
libnss_files-2.3.4.so
-rwxr-xr-x   1 root root   17852 29 lug 18:54 libnss_hesiod-2.3.4.so
lrwxrwxrwx   1 root root      22 29 lug 18:56 libnss_hesiod.so.2 -> 
libnss_hesiod-2.3.4.so
-rwxr-xr-x   1 root root 2261440 29 lug 18:54 libnss_ldap-2.3.4.so
-rwxr-xr-x   1 root root   34316 29 lug 18:54 libnss_nis-2.3.4.so
-rwxr-xr-x   1 root root   42432 29 lug 18:54 libnss_nisplus-2.3.4.so
lrwxrwxrwx   1 root root      23 29 lug 18:55 libnss_nisplus.so.2 -> 
libnss_nisplus-2.3.4.so
lrwxrwxrwx   1 root root      19 29 lug 18:55 libnss_nis.so.1 -> 
libnss_nis-2.3.4.so
lrwxrwxrwx   1 root root      19 29 lug 18:55 libnss_nis.so.2 -> 
libnss_nis-2.3.4.so
-rwxr-xr-x   1 root root   15584 29 lug 18:54 libnss_winbind.so
-rwxr-xr-x   1 root root  706088 29 lug 18:54 libnss_wins.so
-rwxr-xr-x   1 root root   68992 29 lug 18:48 libresolv-2.3.4.so
lrwxrwxrwx   1 root root      18 29 lug 18:50 libresolv.so.2 -> 
libresolv-2.3.4.so

e master.cf si presenta così:

smtp    inet    n       -       y       -       -       smtpd
smtps   inet    n       -       n       -       -       smtpd
  -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes
#submission     inet    n       -       n       -       -       smtpd
#  -o smtpd_enforce_tls=yes -o smtpd_sasl_auth_enable=yes
#628      inet  n       -       n       -       -       qmqpd
pickup  fifo    n       -       y       60      1       pickup
cleanup unix    n       -       y       -       0       cleanup
#qmgr     fifo  n       -       n       300     1       qmgr
qmgr    fifo    n       -       y       300     1       qmgr
#tlsmgr   fifo  -       -       n       300     1       tlsmgr
rewrite unix    -       -       y       -       -       trivial-rewrite
bounce  unix    -       -       y       -       0       bounce
defer   unix    -       -       y       -       0       bounce
flush   unix    n       -       y       1000?   0       flush
smtp    unix    -       -       y       -       -       smtp
showq   unix    n       -       y       -       -       showq
error   unix    -       -       y       -       -       error
local     unix  -       n       n       -       -       local
virtual unix    -       n       y       -       -       virtual
lmtp    unix    -       -       y       -       -       lmtp
#
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
# The Cyrus deliver program has changed incompatibly.
#
cyrus     unix  -       n       n       -       -       pipe
  flags=R user=cyrus argv=/cyrus/bin/deliver -e -m ${extension} ${user}
uucp      unix  -       n       n       -       -       pipe
  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - 
$nexthop!rmail.postfix ($recipient)
ifmail    unix  -       n       n       -       -       pipe
  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp     unix  -       n       n       -       -       pipe
  flags=Fq. user=foo argv=/usr/local/sbin/bsmtp -f $sender $nexthop 
$recipient
smtp-amavis unix -      -       n       -       2  smtp
    -o smtp_data_done_timeout=1200
    -o disable_dns_lookups=yes
127.0.0.1:10025 inet n  -       n       -       -  smtpd
    -o content_filter=
    -o local_recipient_maps=
#    -o relay_recipient_maps=
#    -o smtpd_restriction_classes=
#    -o smtpd_client_restriction=
#    -o smtpd_helo_restrictions=
#    -o smtpd_sender_restrictions=permit
#    -o smtpd_recipient_restrictions=permit_mynetworks,reject
    -o mynetworks=127.0.0.0/8
    -o mynetworks_style=host
#    -o strict_rfc821_envelopes=yes
    -o smtpd_error_sleep_time=0
    -o smtpd_soft_limit_error=1001
    -o smtpd_hard_limit_error=1000



Insomma, non so che pesci pigliare !!!

Aldo