Webmail not active on Kloxo-Mr

[mrtoanhcm]

Dear Mr Mustafa!
I have problem:
* On my server Kloxo-Mr have many hosting- many domain. But only one domain can to use webmail, another domain can't use webmail (Error: website not available).
I don't known repair that! Can you tell me that error?

P/s: On webmail can use, i was setup suscess imap on mobile, outlook.

[MRatWork]

Not able access to webmail.domain.com?. If yes, there are something wrong with your dns setting and try check via intodns.com

[mrtoanhcm]

That intodns:
Warn   Different subnets   WARNING: Not all of your nameservers are in different subnets
Pass   IPs of nameservers are public   Ok. Looks like the IP addresses of your nameservers are public. This is a good thing because it will prevent DNS delays and other problems like
Pass   DNS servers allow TCP connection   OK. Seems all your DNS servers allow TCP connections. This is a good thing and useful even if UDP connections are used by default.
Warn   Different autonomous systems   WARNING: Single point of failure
Pass   Stealth NS records sent   Ok. No stealth ns records are se

[MRatWork]

No critical issue for related to above warning because it's appear if using the same subnet for ns1 and ns2.