Allow the user to send emails to all or selected rows in a particular views display
I wrote an answer somewhat similar to this functionality. 

https://drupal.stackexchange.com/a/195228/53677

Basically, you could create an entityform with an entityreference field for emailable users and a field for your email message. 

Then on your view page, provide an email button and use jQuery to create a link to pre-populate the users you want to email. Use Rules to loop this on entityform save.

The link to the form would have to look like /eform/submit/email-form?field_email_uids=10,12,15,201

It's a bit more work but can give a really nice interface if done right. Your view can be anything as long as you can grab the UIDs. 

Or you could just hide the fields you don't want with css / jQuery. 

Edit: Adding instructions for the jQuery part

Here's a very basic example of the finished result. This can be added to any view setup.



You can of course decide to not use checkboxes and perhaps add a border or background etc. to the whole row. You can do anything you like with jQuery and .parent()etc. to go up the DOM and add/remove classes.

Views Custom Text Field: (The UID and Name fields are hidden above. I use font-awesome on this install. You can use ✓ or something else instead of the )

&lt;a href="#" class="email_box" value="[uid]"&gt;
&lt;i class="fa fa-check"&gt;&lt;/i&gt;&lt;/a&gt;
&lt;span&gt; [name] &lt;/span&gt;


Views Footer Custom Text Field:

&lt;a href="/eform/submit/email-form" id="email_link"&gt;Send Email&lt;/a&gt;


jQuery:

$('.email_box').click( function() {

    // Check if it's clicked + add / remove classes
    if ( !$(this).hasClass('email_checked') ) {
        // Add Class
        $(this).addClass('email_checked');
    } else {
        // Remove Class
        $(this).removeClass('email_checked');
    }

    // Call function below for Email Link
    build_link();

});

// Get all boxes that are clicked and add their value tags to the link
var build_link = function() {
    var email_uids_array = [];
    // Loop checked and add UIDs to array
    $('.email_checked').each( function() {
        email_uids_array.push( $(this).attr('value') );
    });
    // Split array into uids
    var uids = email_uids_array.toString();
    // Create link
    var link = '/eform/submit/email-form?field_email_uids=' + uids;
    // Alter the Email link's href
    $('#email_link').attr('href', link);
};


Some CSS so it makes sense to the user:

.email_box {
  border: solid;
  border-width: 1px;
  border-color: #c2c2c2;
  color: #ddd;
}
.email_checked {
  color: #444;
}
/* Fix Hover / Focus */
.email_box:focus,
.email_box:hover {
  color: #ddd;
}
.email_checked:focus,
.email_checked:hover {
  color: #444;
}


The benefits here are total customization and it should work pretty well.