[RFCI-Discuss] about FQDN for our smtp servers

[mouss]

Jeff Pang wrote:
> Thanks Alex.When the other site receive the HELO command from one IP of our MTAs,does it verify the IP by ptr record,or by A record following the HELO command?
>
>   

This is a question for the recipeitn MTA. some MTAs will reject you if 
your helo doesn't resolve to your IP. some MTAs will reject you you if 
your helo doesn't resolve. some MTAs will accept any helo. to stay on 
the safe line, your helo should resolve to your client IP
    one_of_ip(helo) = client_ip

This is the common understanding of the rfc. many people won't go that 
deep and will only check that your helo resolves. most people will just 
ignore all this because of those many borked sites.

> Yes,smtp.163.split.netease.com is a split DNS used to do the balance between different ISPs.For example,the China Telecom's users should access smtp.163.split.netease.com via these IPs:
> 11.11.11.11
> 22.22.22.22
> ...
>
> But China Network Communication's users should access the same domain name via other IPs:
> 33.33.33.33
> 44.44.44.44
>   
This is because you must set your ip to PI and your relay to sqrt(2). 
come on. don't use addreses you don't own as examples. the example 
network is 192.0.2.*.