Description of problem: in a home computer with IPv4 and IPv6 activated, but only link local IPv6 address, so IPv6 not routable, postfix daemon only tries IPv6 connection with a production mailserver with IPv6 and IPv4 working addresses.

Version-Release number of selected component (if applicable):
Fedora 16
postfix-2.8.7-1.fc16.x86_64

How reproducible:
allways

Steps to Reproduce:
1. Start Postfix with default config
2. In a terminal exec: echo Prueba | mail -s"prueba IPv6" fgozalo0.es
3. 
  
Actual results:
Mail no delivered, in queue.

Logs:
Apr 18 17:40:02 fedora16 postfix/pickup[2452]: E5AB140C88: uid=0 from=<root>
Apr 18 17:40:02 fedora16 postfix/cleanup[2891]: E5AB140C88: message-id=<20120418154002.E5AB140C88.es>
Apr 18 17:40:02 fedora16 postfix/qmgr[2453]: E5AB140C88: from=<root.es>, size=442, nrcpt=1 (queue active)
Apr 18 17:40:03 fedora16 postfix/smtp[2893]: connect to mx02.puc.rediris.es[2001:720:418:ca00::8]:25: Network is unreachable
Apr 18 17:40:03 fedora16 postfix/smtp[2893]: connect to mx01.puc.rediris.es[2001:720:418:ca01::131]:25: Network is unreachable
Apr 18 17:40:03 fedora16 postfix/smtp[2893]: connect to mx01.puc.rediris.es[2001:720:418:ca01::130]:25: Network is unreachable
Apr 18 17:40:03 fedora16 postfix/smtp[2893]: connect to mx02.puc.rediris.es[2001:720:418:ca00::4]:25: Network is unreachable
Apr 18 17:40:03 fedora16 postfix/smtp[2893]: connect to mx02.puc.rediris.es[2001:720:418:ca00::3]:25: Network is unreachable
Apr 18 17:40:03 fedora16 postfix/smtp[2893]: E5AB140C88: to=<fgozalo0.es>, relay=none, delay=0.36, delays=0.13/0.01/0.23/0, dsn=4.4.1, status=deferred (connect to mx02.puc.rediris.es[2001:720:418:ca00::3]:25: Network is unreachable)


Expected results:
Mail delivered.


Additional info:

# ifconfig p3p1
p3p1      Link encap:Ethernet  HWaddr 00:1C:23:FD:13:30  
          inet addr:192.168.0.33  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::21c:23ff:fefd:1330/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3800 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4169 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:2340843 (2.2 MiB)  TX bytes:894002 (873.0 KiB)
          Interrupt:17 

# host -t mx alumno.uned.es
alumno.uned.es mail is handled by 20 mx02.puc.rediris.es.
alumno.uned.es mail is handled by 20 mx01.puc.rediris.es.

# host mx02.puc.rediris.es
mx02.puc.rediris.es has address 130.206.18.134
mx02.puc.rediris.es has address 130.206.18.3
mx02.puc.rediris.es has address 130.206.18.4
mx02.puc.rediris.es has address 130.206.18.8
mx02.puc.rediris.es has address 130.206.18.132
mx02.puc.rediris.es has IPv6 address 2001:720:418:ca01::134
mx02.puc.rediris.es has IPv6 address 2001:720:418:ca00::3
mx02.puc.rediris.es has IPv6 address 2001:720:418:ca00::4
mx02.puc.rediris.es has IPv6 address 2001:720:418:ca00::8
mx02.puc.rediris.es has IPv6 address 2001:720:418:ca01::132

# host mx01.puc.rediris.es
mx01.puc.rediris.es has address 130.206.18.131
mx01.puc.rediris.es has address 130.206.18.7
mx01.puc.rediris.es has address 130.206.18.10
mx01.puc.rediris.es has address 130.206.18.11
mx01.puc.rediris.es has address 130.206.18.129
mx01.puc.rediris.es has address 130.206.18.130
mx01.puc.rediris.es has IPv6 address 2001:720:418:ca01::129
mx01.puc.rediris.es has IPv6 address 2001:720:418:ca01::130
mx01.puc.rediris.es has IPv6 address 2001:720:418:ca01::131
mx01.puc.rediris.es has IPv6 address 2001:720:418:ca00::7
mx01.puc.rediris.es has IPv6 address 2001:720:418:ca00::10
mx01.puc.rediris.es has IPv6 address 2001:720:418:ca00::11