Error mailing multiple addresses in Recipients field

Issue Summary

In a freshly created Tell a Friend node the Recipients field help text states: "Enter email addresses one per line". When I do so, only the last recipient address in the list receives mail. For the other addresses the result is an error message: "Recipient email address is invalid."

When I put the mail addresses in one, comma-separated string, all addresses receive mail without an error. This only succeeds when leaving out all spaces between addresses.

Is the error probably a result of the way the Recipients input field is sanitized?