Add a column in your sheet with "cc" as header and put Cc recipients in this column.
Add a column in your sheet with "bcc" as header and put Bcc recipients in this column.
Make sure to add exactly 'cc' or 'bcc' in lowercase as Mailmeteor is case sensitive.
Adding multiple Cc or Bcc recipients
If you want to put several addresses in Cc or Bcc, just separate them with comma.
Each recipients you add in Cc or Bcc counts in your sending quota.
Here's a video to show you how to add cc/bcc recipients in Mailmeteor: