By default, your daily email limit is set to 20 for improved deliverability.
If you’re sending out, say, 100 emails every day for a prolonged period of time (especially if the pitches are very similar, for example, for link building), you run an increased risk of triggering spam filters.
This will have a tremendous impact on your deliverability and engagement rates because people will simply never see your pitches.
Learn how you can change your daily email limit here: How do I increase my daily email limit?