On 03/12/2015 19:16, Timothy Pearson wrote:
> As you can probably infer the main problem is that my ISP doesn't provide
> enough IP addresses (at a cost I am willing to pay) for all the services
> running here.  From what I understand multiple rDNS records for the same
> IP is likely to cause more problems than it's worth as well.
>
> After the servers are relocated next year there should be more IP
> addresses available, which will make this problem go away.  I'm not all
> that keen on changing the HELO string as it isn't technically the domain
> that's identifying, it's that specific mail server, and over time there
> may be more than one mail server (for redundancy, etc.).
>
> Since this has affected only one person in 5 years, I'm treating this like
> the DKIM problem for the moment; give it more time and it might go away.
> :-)
>
> Tim
>

It's certainly up to you how you run things, but it won't go away. :)

rDNS is really only important for mail servers but it is becoming 
increasingly important as the amount of spammers reaches astronomical 
proportions. An increasing number of servers will reject mail due to 
failed rDNS.

You could just get your ISP to point your IP's rDNS to your mail server 
hostname and your done. You won't need it for any of your other services 
and it will not affect any of your A records or CNAME records.

Regards,
Mike.

-- 
Mike Howard