In the last video we added in a line of code to create the subdocument collection, specifically this line:

recipients: recipients.split(',').map(email => ({ email: email })), 

Just one issue - remember that the list of emails is supposed to be separated by commas and spaces.  We split by commas here, but there still might be some trailing or leading spaces on each email.  As such, we should make sure that we cut out any extra white space.  So make sure you change this line of code to read:

recipients: recipients.split(',').map(email => ({ email: email.trim() })),