We previously had email accounts hosted at Microsoft Live platform for one of our domains say abc.com. Which I have migrated to Office 365 Small Business accounts. Name server changes took place nearly 10 hours ago and I have also migrated old emails using PST files. Many test emails from Gmail account landed in the Office365 portal fine which tells me that mail started flowing to the Office365 (Exchange Online mailboxes).
We have a major issue with some emails still going to the old mailboxes hosted at Microsoft Live platform. Specially from our in-house exchange server. None of the emails from this exchange server land in Office 365. Now that we don't have any control of the DNS records and the MX records correctly pointing to Office365 what is still wrong??
Could there be a DNS entry or similar on our Exchange which I need to change/edit?
This is an urgent issue and needs to be resolved quickly.
Thanks for your help!