@Pavani_Regulagedda - you can use the below html to open the default email editor with pre-populated values. If outlook is your default client then it should open the new email with pre-populated values.

<a href="mailto:[email protected][email protected]&[email protected]&subject=Summer%20Party&body=You%20are%20invited%20to%20a%20big%20summer%20party!" target="_top">Send mail!</a>

@Pavani_Regulagedda

This can be done by using a Paragraph rule. In section call a label wherein call a paragraph rule.

In the Paragraph rule, you'll be having an option to add a link where pass the Protocol type as "Others" and URL as "mailto:[email protected]". And on clicking the URL again you'll get option to add Subject body to that link.

@Pavani_Regulagedda 

To open an Outlook email with a predefined subject and body when a button is clicked, you can use the mailto: protocol. Add a button in HTML and use JavaScript to attach a click event. In the event handler, create a mailto link like mailto:[email protected]?subject=Your%20Subject&body=Your%20Message, replacing the recipient, subject, and body with your desired values. Use encodeURIComponent for the subject and body to handle special characters. Then, set window.location.href to the mailto link to open the default email client (e.g., Outlook) with the email ready to send. Note that the "From" address is determined by the user's Outlook account and cannot be set via mailto. This approach works only if Outlook is the default email client on the system. For more advanced control, like setting the "From" address, you'd need to use the Microsoft Graph API