Hi jiraporn.boom,
Welcome to Microsoft Community, we are glad to assist you here.
Based on your description, we understand you can send but receive emails on your M365 account.
According to the information you provide, it seems there was no MX record in your domain, to identify it, please go to M365 admin center and find the domain page as below:
Check your affected domain and if your domain is not in healthy status, please click it and follow the steps to complete the domain setup or contact your local domain provider to update MX records and other records correctly from their side.
Thank you for your time and hope this is helpful,
Regards,
Microsoft Community