Adding subscribers by importing spreadsheet allows invalid emails

[ghost]

Expected Behavior

Emails that aren't valid to be not imported from the spreadsheet

Current Behavior

All subscribers are imported, even the ones with invalid emails

Possible Solution

Steps to Reproduce

1. Load subscriber with invalid email (Test@test or Test) to the spreadsheet
2. Import said spreadsheet

Spreadsheet with invalid emails that were able to be imported to SendPortal (Save it as .csv):
test.xlsx