Dear Willem Martins,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
If you migrate your emails to Microsoft 365 Business Standard using your domain name, the emails will be routed through Microsoft's servers instead of your host provider's servers. This means that the reliability issue you are experiencing with your host provider's email services should be resolved.
However, you will need to make sure that you have properly configured your domain's DNS settings to point to Microsoft's servers for email delivery.
You can find instructions below:
- Add/verify your domain in your Microsoft 365 Business Standard subscription. Please follow the information in the article: Add a domain to Microsoft 365 - Microsoft 365 admin | Microsoft Learn.
- Add or edit custom DNS records to change your host to Microsoft: Add or edit custom DNS records.
(Since your concern is mainly about the email exchange, the key DNS record should be MX record, please make sure it's configured correctly following the guidance.)
I hope the information helps! If there is any update or I misunderstand you, please feel free to let me know. I will continue to assist you. Your understanding and co-operation are highly appreciated.
Thanks for your precious time. Have a nice day.
Sincerely,
Sherry | Microsoft Community Moderator