By default EZ Importer will NOT email your customers. If you do want your customers to get emails on import you can use the email customer on import feature by turning it on in your data mapping. For detailed instructions on how this works click here.

You should audit all the apps in your store as they may email your customers during order creation. We recommend you do a small test to ensure no customers get an email before running your full import.

You may want to turn off the notifications on your store so shopify doesn't email you on every import. You can read more about this in our docs.