postfix/mail: server blacklisted -- what have I done wrong?

[Derek Broughton]

Lea Gris wrote:

> Matt Price a écrit :
>> -----------------
>> so, I followed the link, which ultimately led me to this page about HELO
>> misconfiguration:
>> http://cbl.abuseat.org/lh.html
>> 
>> Still wish I knew what "HELO" was about, but at least it helps.
>> Turns out that I I had been having some trouble in the last few weeks
>> with rejected mail complaining about "localhost.localdomain".  Finally
>> fixed it a few days ago by editing /etc/postfix/main.cf
>> ----
>> # myhostname = localhost.localdomain
>> myhostname = a.legitimate.domain.name
>> ----
>> 
>> so a couple of questions follow for me:
>> 
>> 1 - is this the likely cause of the problem?  THat is, have I already
>> fixed a problem that has only just now arisen?

You've fixed a problem which has only recently resulted in your address
being blacklisted - not quite the same thing.

>> 2 - If localhost.localdomain is ALWAYS a broken value for myaddress, how
>> does it come about that this is even a configuration option?  SHould I
>> for instance file a bug?

It's not a "configuration option".  It's a default value which you're
supposed to change in debconf before you ever configure your postfix
server.

> Either you have a dynamic IP address or an address listed as such in the
> related RBLs.

I don't think it said that.  

> Either the distination MX check for proper FQDN which can not be with
> dynamic IP address from internet providers that may not have proper
> reverse DNS either.

IIf they're really blacklisting servers for sending mail from FQDNs that
aren't MXes they should be shot.  There's no reason a _sending_ mail
address should be a valid MX.  There's also no reason that it should have
'proper' reverse DNS.  My _proper_ domain, pointerstop.ca, is on a hosting
service.  A reverse lookup on the IP is always going to show
cedars.serverforest.com.  There's nothing wrong with that, either in
practice or in the various mail RFCs.
> 
> The right thing to do is configure a Postfix RelayHost to your Internet
> Provider smtp relay such as smtp.myprovider.tld

Generally true.
-- 
derek