Step 4: Update the accepted domains list in O365

  1. Navigate to the Admin CenterExchange screen
  2. Go to the mail flow => accepted domains option

    • Give a suitable Name (the image below shows the sample domain name
    • Enter your domain in the Accepted Domains list. (The image below shows the configuration for domain Substitute with your domain name.)
    • Choose the Internal Relay option
    • Select the Accept mails for all subdomains option
    • Save the accepted domains list