On 6/21/2013 10:24 AM, Titanus Eramius wrote:
> I've searched several times about information on the PTR record, and
> what myhostname in main.cf should be. The problem is not the
> information, but the fact that I struggle to understand it...
Ideally, the PTR, A record, and HELO hostname should all agree.
> This server runs with the IP address 188.8.131.52 from a hosted VPS, and
> using dig to do a reverse lookup gives
There doesn't appear to be a matching A record for that PTR, so the
setup is incomplete. Postfix will label such a host as "unknown".
Most sites (but not all!) will still accept your mail.
Best to request your hosting company to give you a custom PTR with
your domain name, something like smtp.example.com, mx1.example.com,
mail.example.com, etc. so your server looks like a mail server and
not a random infected bot. If this host handles several domains,
just pick one for the PTR and A record. No need to list them all.
Whatever PTR you end up with, there should be a matching A record
with the server address.
> Does this means I should use 46-21-105-38-static as myhostname?
While technically correct to use the
46-21-105-38-static.serverhotell.net hostname, that's the same name
a random infected bot will use and should be avoided.
I would still suggest a myhostname setting that makes you look like
a mail server instead of a random bot, even if it doesn't match the
PTR. Make sure you also have an A record set for the hostname that
points back to your server's IP.
-- Noel Jones