Send Google Drive Files without Sharing

I am interested in the Mail Merge Google Add on, however, I have a question regarding access for the attachment. May I know if the access restriction set at the file in Google Drive affects the person who opens the attachment at the merged email? To put it in a simple example: A Google file named “ABC” is set with access restriction only to Peter and Mary in the Google Drive However, I want to use this add-on to send mass mail with the attachment of the ABC file to 100 people. Do I need to grant access of the file to these 100 people at ABC file in Google Drive so that they can have access to that? Or will the file be downloaded and attached to the mail so that even people without access to Google Drive can open the file?