You can send as much Corporate or Transactional emails you need. There is really no limit on the amount of emails Protected by Perimeter you can sent. But its strongly forbidden send any type of Marketing email campaigns through Perimeter. Marketing emails are mostly newsletters (and spam to a certain extent), and transactional emails are confirmation emails etc. The former is meant to be sent in bulk and the latter is meant to be sent individually.
Transactional email: Think about when you sign up to your website or ecommerce. When you finish signing up, you will receive a “please confirm your email” message. After confirming your email, you will get a “welcome to xxx ecommerce” message. When you buy something, you will get a “your order detail” message. These are transactional emails. Basically, you will get transactional emails based on your actions.
Marketing email: If you are sending newsletters to many people at once, that’s marketing email. They are messages that you send in bulk to inform people or promote your service.
There are some specialized marketing mail services you can use instead: