Exchange hybrid mail flow

We have our DNS records hosted by an ISP who is also managing our website which were recently changed over to a different provider. They recreated our zone file with the A records pointing to the correct public IP addresses but when I do an nslookup, using a public DNS server such, on the some of the entries they resolve to public IP addresses other than the ones configured. For example if I do nslookup it resolves to 192.252.XXX.XXX yet the A record entry points to 12.154.XXX.XXX. Having an issue with our hybrid email environment. Office365 to Office365 works fine but Office365 to onprem does not. The onprem is nated to that 2nd IP address
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Vasil Michev (MVP)Commented:
How much time has passed since you updated the record and what's the TTL on it? Make sure you dont hit any cached record and do the tests from ExRCA to check what Office 365 "sees":
You should have probably made the change over the weekend...

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InSearchOfAuthor Commented:
These changes were made over a month ago
InSearchOfAuthor Commented:
What about my question regarding the public IPs?
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AmitIT ArchitectCommented:
Without getting actual IP's and network diagram, it is difficult figure out the issue. I did something similar migration last year and took me 6 months to complete it.
InSearchOfAuthor Commented:
Hmmmm. I get that but it looks like my problem may be with the public DNS entries. If I do an NSlookup on a domain name email entry shouldn't I get back the configured IP address?
InSearchOfAuthor Commented:
Things are working now. I was to get a hold of our DNS provider and they were able to rectify the issue. Thanks for the help.
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