pippinsplugins/Easy-Digital-Downloads — pull request #547 by innerbot (2012-12-09 01:45:25+00:00)
Title: implementing #564 parse email template tags in subject

So, I've just taken the call to edd_email_templage_tags() which is ran on the message body and in line 49 of email-functions.php applied the same function to the subject line of outgoing email receipts.

This worked perfectly for me!