Migration 365 mail to Gmail MX record issues

[dougabrams]

So with Google Classroom etc we finally decided to swap all our school email from Microsoft 365 to Gmail (without changing the email addresses) but we have a glitch...

We allowed a period of 2 weeks over Christmas where we tried not to use school email, to allow time to replicate our old historical emails, copying from Microsoft 365 to Gmail.

Then to get the sending and receiving to work, the MX records for our domain were changed on Jan 2nd and our new school Gmail accounts send and receive beautifully now.

 

However, Microsoft (our old email system) did not seem to get the message to stop working. So our problem is if you send an email from your old school Microsoft 365 account to someone with a Microsoft account they still get it, but not if you send the email from your new Gmail account.

 

This is a massive problem as a parent with a Microsoft email address doesn't get any of our emails from our Gmail.

 

Any ideas anyone?

 

Many thanks, Doug

[snagrat]

I can’t see this is a Microsoft problem, more a Google problem.

 

Or even a problem with the recipients account.

[john]

Why would you be sending from o365 if you have moved over?

 

If this is an accident / someone forgets put a transport / mail flow rule to block / reject any outbound mail to help stop people doing it.

 

Why its happening I would guess that Microsoft are going we have that domain don't do external look ups so it's in effect an "internal" mail from your o365 to say Hotmail.com email so that's why it's working.

 

What bounce back are you getting to your Google one when emailing Microsoft services?

 

Is it that you have forgot to change some dkim or spf records over perhaps?

 

Have you turned off the mail stuff in o365 if you have now moved over?

Edited January 7, 2020 by john

[Primus]

So email from O365 to O365 works but email from G Suite to O365 doesn't?

 

Does G Suite to other external domains work? Eg. can you email an account that isn't hosted by either G Suite or O365?

 

Have you correctly setup SPF, DKIM, DMARC etc to reflect the changes you have made now in moving to G Suite as these emails could potentially now be flagged as spam to be rejected etc?

[chaplic]

In O365, set the domain in question to Internal Relay. I assume the migrated mailboxes are gone. Will be delivered to O365 then sent out. Ensure your SPF record still has O365 referenced.

[dougabrams]

Thanks Chaplic, I found Microsoft Exchange Admin and switched our domain from Authoritative to Internal Relay which made mail from any external Microsoft account use the MX records to send it to our new Gmail system now.

[kingoranks]

@dougabrams, we are about to do the same switch. I have a couple of questions.

Can you help with the steps you went through.

Did you contact your ISP?

 

Thanks