Using Email Line Manager function in learning is not working correctly

Summary:

When trying to email line managers directly from within a course, an extra exclamation mark is being added to the list of email addresses, which prevents the email from sending.

Has anyone else come across this?

Content (please ensure you mask any confidential information):

When emailing line managers from within a course (Learners > More Actions > Email Line Manager), the system is adding in a extra 'something' that Outlook doesn't like and prevents the email from being sent. Deleting it allows the email to be sent, so it is only a minor annoyance. It does't do it for employees.

I just wondered if anyone else had come across anything similar and knows what is causing it to happen?