How to Calculate Your Email Sending Limit (Without Guesswork)

If you've ever wondered how many emails to send or how many inboxes to set up for your cold email funnel, this post is for you. Here's the no-fluff method to reverse-engineer your email sending limits based on your business goals. Whether you're a sales pro, marketing lead, or founder in the trenches, this guide breaks it all down step by step.

By the end, you'll understand how to calculate:

• The number of emails to send daily.

• The number of inboxes you’ll need.

• The total cost of your email funnel (yes, we'll crunch the numbers).

Let's get to business.

Step 1: Start with Your Business Goals

Your email sending limit isn’t random. It should be based on your business objectives. Here's an example calculation:

• Target Clients per Month: Say your goal is to onboard 10-15 clients a month.

• Close Rate: You close 50% of qualified appointments (For the sake of easy maths).

• Required Appointments: To hit your target, you need 20-30 qualified appointments monthly.

Now that you know your objective, it’s time to work backward.

Step 2: Understand Lead-to-Appointment Metrics

How many leads do you need to book 30 appointments? This depends on your current funnel efficiency.

• Lead-to-Appointment Conversion Rate: If 75% of your leads turn into booked appointments, you’ll need about 40 leads to book 30 appointments.

• Leads per Email: Say your average is 1 qualified lead per 1,000 emails sent.

With this, we can calculate:

• Emails Needed Per Month = 40 leads × 1,000 emails/lead = 40,000 emails/month.

Easy math, right?

Step 3: Break It Down to Daily Email Volume

There are roughly 20 working days per month. To hit your goals consistently, divide your monthly email volume by working days:

• Daily Emails Needed: 40,000 emails ÷ 20 days = 2,000 emails/day.

But wait—this isn’t the end of the story. Every email requires an inbox. Let's figure out how many you’ll need.

Step 4: Calculate the Number of Inbox Accounts

To maintain good email deliverability, you should send a limited number of outbound emails per inbox daily. I recommend sticking to 25 outbound emails per inbox per day (play it safe; you're not Netflix).

Now, divide your daily email volume by emails per inbox:

• Total Inbox Accounts Needed = 2,000 emails/day ÷ 25 emails/inbox = 80 inboxes.

Yes, you’ll need around 80 inboxes to send 2,000 emails daily while avoiding spam folders. But what about the costs? Let's crunch those numbers.

Step 5: Estimate the Cost of Your Email Funnel

Setting up and running an email funnel isn’t "free magic." Here’s how to calculate its cost:

A. Domain Costs

• Each domain can hold 2 mailboxes. For 80 inboxes, you’ll need 40 domains.

• Cost per domain (e.g., `.com`) = $10/year.

• Total Annual Domain Cost = 40 domains × $10 = $400.

B. Inbox Costs

• Cost per inbox = $5/month (Endy's GSuite/Outlook rate; adjust if needed).

• Monthly Inbox Cost = 80 inboxes × $5 = $400/month.

C. Total Setup Cost

• First-month cost = Domain setup ($400) + Inbox cost ($400) = $800 upfront.

D. Recurring Costs

• Monthly cost (after setup) = Inbox cost = $400/month.

Keep in mind, these costs don’t include the sequencer software or lead lists you might be using (e.g., Instantly.ai or Smartlead.ai).

Step 6: Optimize for Efficiency (Optional)

Once your setup is live, monitor and adjust as needed:

• Warm-Up Period: Never start blasting 25 emails per inbox immediately. Gradually ramp up volume over a week or two.

• Inbox Segmentation: Divide inboxes across different providers (Google, Outlook, etc.) to reduce reliance on one platform.

Doing this right ensures emails land where they’re meant to. Trust me—it's worth it.

TL;DR Cheat Sheet

If you’re short on time, here’s how it breaks down:

1. Target Onboarding = 10-15 clients/month.

2. Emails Needed = 40,000/month (or 2,000/day).

3. Inbox Needed = 80 inboxes (at 25 emails/day per inbox).

4. Cost = $800 setup, $400/month recurring (including domains & inboxes).

Simple, scalable, effective.

Why These Calculations Matter

Cold email isn’t just a numbers game; it’s a strategic play that can either skyrocket your business or land you in spam doom. These calculations help you:

• Ensure your emails hit the right inboxes.

• Avoid burning domains or violating email limits.

• Stay cost-efficient while scaling.

Think of these numbers as your roadmap to a predictable, scalable email outreach system. It’s math—but fun (and very profitable) math.

Level Up Your Outreach Funnel Today

Hate doing the math? Platforms like Instantly.ai or Smartlead.ai simplify inbox management and sequencing for busy pros like you.

Or, if you’d rather not deal with setup headaches at all, we’ve got you covered:

• Done-for-you cold email infrastructure setup.

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Click here to schedule a chat with us and start optimizing your email funnel today.

Happy emailing ✉️!