Ultimately, the number of emails you send will depend on the type of your business, your industry, and your prospects. However, before you get to that number, ensure you first build out a targeted prospect list and warm up your email account.
Use tools such as ZeroIn to find relevant prospects according to your ICP.
When you have your list, begin by sending a number of 5 to 10 emails per day for approximately three to four weeks. Then, gradually ramp up the volume of emails you send each day until you reach your desired target number.