nslookup different results on internal and external DNS

[the_quick]

Hi Guys

 

We have bit of strange problems. We trying to reply to email from one company girlguiding.org.uk - but when we recieve emails they always come with addidtional bits and look like this @www.girlguiding.org.uk.cdn.cloudflare.net

 

They are now telling us that our DNS is looking on cname record instead of MX record. So I started playing with nslookup for MX records.

 

From our external dns we get this:

Non-authoritative answer:
girlguiding.org.uk      nameserver = ns1.livedns.co.uk
girlguiding.org.uk      nameserver = ns2.livedns.co.uk
girlguiding.org.uk      nameserver = ns3.livedns.co.uk
eu-smtp-inbound-1.mimecast.com  internet address = 91.220.42.201
eu-smtp-inbound-1.mimecast.com  internet address = 91.220.42.211
eu-smtp-inbound-1.mimecast.com  internet address = 91.220.42.241
eu-smtp-inbound-1.mimecast.com  internet address = 195.130.217.201
eu-smtp-inbound-1.mimecast.com  internet address = 195.130.217.211

 

But from our internal DNS we get this wierd adresess:

Non-authoritative answer:
girlguiding.org.uk      canonical name = girlguiding.cloud.thisiszone.com
girlguiding.cloud.thisiszone.com        canonical name = www.girlguiding.org.uk.cdn.cloudflare.net

 

 

Can anyone point me to right direction? DNS sits on our DCs - Windows 2008 R2

 

Appreciate any help

Thx

Kris