Ned Slider wrote:
I didn't find anything wrong in the document in question (http://wiki.centos.org/HowTos/postfix), except that a couple of packages mentioned (ystem-change-mail*) don't seem to exist in CentOS-6.
That was for switching the default MTA in EL5. As Postfix is already the default in EL6 it is simply not needed.
That's not the case. If you upgrade from CentOS-5 to CentOS-6, which I imagine the vast majority of people did, then sendmail remains the current MTA. However, this is only a tiny point, since the document mentions "yum remove sendmail" as an alternative.
Firstly, after following the instructions meticulously, I found that I could not send out mail because (according to /var/log/maillog) the From address was tim@localhost.localdomain , and this was rejected by the recipient host or rather his ISP.
tim@localhost.localdomain MAIL FROM domain does not exist (in reply to MAIL FROM command)
I cured this by adding tim tim@gayleard.eu to /etc/hosts . I don't know if this is the best way to go about it?
This is typically caused by having your hostname set to localhost (or loaclhost.localdomain). Your hostname should reflect your fqdn.
If you mean $myhostname in /etc/postfix/main.cf then that is not the cause; it was set to my fqdn. Also it is set in /etc/sysconfig/network. And it is the name given by "uname -a". I'm not sure where else it can be given?
After correcting this, I found my email was still rejected, with the message "Blacklisted by Spamhaus"! I read in http://www.spamhaus.org/pbl/query/PBL814205 that 'the reason is simply that you need to turn on "SMTP Authentication"'
The bit at the top of the Spamhaus link says it all really - as a matter of *policy*, Spamhaus and/or your ISP has decided that you shouldn't be sending email direct from that IP address as it's residential / dynamic / whatever. Either way, as a result 90% of the internet is going to reject your mail. You will need to relay all outbound email through your ISPs smarthost to achieve any sort of deliverability.
Exactly. So perhaps this should be mentioned in the CentOS document http://wiki.centos.org/HowTos/postfix?