Deleted DNS zones still in use?

[myfprod]

Hi,

On my domain, I used to have email adresses linked to my hoster server, now I am using Microsoft 365 to manage my emails.

On that server there are my company’s email adresses and those of another company.
Now that we are using Microsoft 365 email adresses, we still receive emails from this other company to our former emails adresses on our hoster’s server.

We submitted the issue to the hoster that told us our dns zones were correct and the issue comes from cloudflare.
I can indeed confirm the dns zones are correct as :

• I checked them
• We use the Microsoft tool to automatically configure the dns zones when we linked our domain name to Microsoft 365.

We also have this issue on another server with domains both managed by cloudflare.

Has someone an idea of where this could comes from ?

Thanks

[domjh]

Hi @myfprod,

@myfprod

we still receive emails from this other company to our former emails adresses on our hoster’s server

So to make sure I understand, domainA and domainB both had their emails hosted on the same server. domainA now moved to Microsoft, but emails sent from domainB → domainA still show up on the old server, not at Microsoft?

If that is the case, I imagine that the server is delivering the emails locally and not checking the domains authoritative DNS for the MX records.