Trigger sent before user is added in user group so no email is sent
You can programmatically trigger a notification email using the Sprout Email service layer. Notification Emails are sent via the SproutEmail_DefaultMailerService using the sendNotification() method:

craft()-&gt;sproutEmail_defaultMailer-&gt;sendNotification($campaign, $object);



$campaign needs to be a SproutEmail_CampaignModel
$object, in your case, would be the Craft UserModel (and more generally is any object that you want to make available to your email templates