Teams and third-party mail server

[GabrieleBrunero]

Hello.

Our customer has a huge issue that I'll try to explain in few steps.

1. They have M365 Business Standard licenses.
2. They are using an external mail server (not Exchange nor Google).
3. By default, when creating Teams meeting, mails would be sent from "@domain.onmicrosoft.com". They didn't like that, because people are unable to reply to it and to start meetings from own calendar.

Does anyone have any idea to how can we force Teams to send email invites with their mail server and/or domain (not onmicrosoft.com) without fully transferring email to Microsoft Exchange?

Many thanks.

With kind regards.

GB

[#2]

I believe that all they need to do is to add their domain to the tenant and set as default

[#3]

Thanks Ed, but I think that it is not that simple...
Do you have experience?

[#4]

I think this is exactly what Ed said.