A Postfix configuration question

[Colin Law]

On 24 November 2015 at 00:45, Tom H <tomh0665 at gmail.com> wrote:
> On Mon, Nov 23, 2015 at 11:08 PM, Colin Law <clanlaw at gmail.com> wrote:
>>
>> I have set up Postfix for the first time, on a server, setting
>> mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
>> smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated
>> defer_unauth_destination
>>
>> and every couple of hours I am seeing, in syslog
>> Nov 23 20:38:06 10955 postfix/smtpd[21510]: warning: inet_protocols:
>> disabling IPv6 name/address support: Address family not supported by
>> protocol
>> Nov 23 20:38:06 10955 postfix/proxymap[21511]: warning:
>> inet_protocols: disabling IPv6 name/address support: Address family
>> not supported by protocol
>> Nov 23 20:38:06 10955 postfix/smtpd[21510]: warning: hostname
>> co.la-paz.az.us does not resolve to address 24.121.225.29
>> Nov 23 20:38:06 10955 postfix/smtpd[21510]: connect from unknown[24.121.225.29]
>> Nov 23 20:38:06 10955 postfix/anvil[21512]: warning: inet_protocols:
>> disabling IPv6 name/address support: Address family not supported by
>> protocol
>> Nov 23 20:38:07 10955 postfix/smtpd[21510]: disconnect from
>> unknown[24.121.225.29]
>>
>> Is this just someone trying to relay through me, and do I need to do
>> anything about it?
>
> 1) Re " warning: inet_protocols: disabling IPv6 name/address support:
> Address family not supported by protocol"
>
> You mustn't have ipv6 enabled. The warning'll go away if you change
> mynetworks and inet_protocols (the latter might even be enough) to be
> ipv4 only.

I have set
inet_protocols = ipv4
mynetworks = 127.0.0.0/8

and the warning has gone.

>
> 2) Re "postfix/smtpd" messages
>
> You have "mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128"
> so you must've chosen the "local only" debconf setting when installing
> postfix. Did you then edit "/etc/postfix/main.cf"?

I realised that since I only need postfix for sending mail from the
server I could set
inet_interfaces = localhost
so that it only listens for locally generated requests.  That seems to
have sorted everything.

Thanks Tom and David.

Cheers

Colin