Hi Cameron,
Based on your description, after changing name servers to Microsoft Office 365, some of your emails are received in Office 365 while others are in Google Apps.
Before moving on, I’d like to confirm the following information:
1.Please tell me your domain name so that I can do further troubleshooting. I have sent you a private message for that, please follow these steps:
• Go to the Your details section on the right side of the community site.
• Click Private messages.
• Click the subject title of the response to read the message.
• You can reply by using the form in this display.
• Click Submit Reply.
2.Please give me the mail header of the emails received in Office 365 as well as in Google Apps.
To get the mail header in OWA:
• Open an email.
• Click “Message Details” on the top.
• The “Internet Mail Headers” are in the “Message Details” window.
To get the mail header in Outlook:
• Open an email.
• Click “File” - >“Properties”
• The “Internet Headers“ are in the “Properties” window.
In addition, this issue may be solved automatically after 72 hours since you change the name servers.
Thanks,
Allen Zhang