Attaching an email to the communication tab in transaction record

Scenario:

Want to see the sent emails in the message list in communication tab in the sales order (Transaction record)

Solution:

Add the parameter “options.relatedRecords” to the email.send(options), and give the transaction records id as value for this parameter for attaching the mail to transaction record

options.relatedRecords : Object that contains key/value pairs to associate (attach) the Message record with related records (that is, transaction, activity, entity, and custom records).

Sample code snippet:

email.send({
    author: senderId,
    recipients: recipientId,
    subject: 'Test Sample Email Module',
    body: 'email body',
    attachments: [fileObj],
    relatedRecords: {
           entityId: recipientId,
            customRecord:{
                  id:recordId,
                  recordType: recordTypeId //an integer value
                  }
      }
});