If your email performance is good (When you get more than 8% opens and less than 3% bounces) then the daily limit for your account gets upgraded automatically every 24 hrs. Good email performance is also judged on multiple factors like high open rate, no user complaints, minimal bounces, and others.
You can also buzz us on Online chat or send us an email on support@pepipost.com so that we can consider your request to check the feasibility of increasing your daily limit of sending emails.