1. Login to your Zoho Mail account. Click on the email for which you need to get the message id.

2. Click on the Dropdown icon in the right-corner > Select 'Show Original'.

3. A new browser tab or window will open with the source of the email message in which you will find the Message Id.

1. Login to your Gmail Account. Click on the email for which you need to get the message id.

You can refer the steps in this link to know how to find the Message Id in Outlook.