How to Calculate Your Email Cost for SMTP Rebilling

By Sparkforge Support Team ·Last reviewed May 3, 2026

Divide your SMTP plan's monthly price by the number of emails included. The result is your per-email cost, which you enter in Sparkforge to calculate rebilling markup.

Setting up email rebilling in Sparkforge requires your base per-email cost from your SMTP provider. The math is simple, but you have to look up the right numbers in your provider's billing dashboard.

Calculate Your Per-Email Cost

  1. Log into your SMTP provider (Mailgun, SendGrid, etc.).
  2. Open the Plan or Billing section.
  3. Note the monthly plan cost and how many emails are included.
  4. Divide cost by email volume.

Example: Mailgun's $35/month plan includes 50,000 emails. $35 ÷ 50,000 = $0.0007 per email.

Enter that value in your Sparkforge SaaS sub-account under Email Resell Settings, then set your markup.

Picking an Email Provider

Sparkforge Email

The simplest option. Sparkforge Email is built in and removes the need to sign up for Mailgun or another third-party SMTP provider. Enable it and email sending and receiving works inside Sparkforge.

Mailgun

Common for agencies managing bulk email across multiple locations and domains. Pairs well with sub-account-level domain control.

Other SMTP Providers

Supported, but Sparkforge recommends Mailgun or Sparkforge Email for full email statistics tracking (opens, clicks).

Which Should You Use?

  • Sparkforge Email enabled: you do not need Mailgun. Sparkforge Email handles sending and receiving on its own.
  • Sparkforge Email not enabled: connect Mailgun (typical) or another supported SMTP provider.

Frequently Asked Questions

What is a typical per-email cost?

For Mailgun's $35/month plan with 50,000 emails, the per-email cost is $0.0007. Higher volume plans drop the per-email rate further.

Where do I enter my email cost in Sparkforge?

Inside the SaaS sub-account, under Email Resell Settings. Enter the calculated per-email value, then set your markup with the slider.

Do I need Mailgun if I use Sparkforge Email?

No. Sparkforge Email replaces Mailgun for sending and receiving once enabled.

Frequently Asked Questions

How do I find my per-email cost?
Log into your SMTP provider, find the included email volume on your plan, and divide the plan cost by that number. Example: $35 / 50,000 = $0.0007 per email.
Do I need Mailgun if Sparkforge Email is on?
No. Sparkforge Email replaces third-party SMTP for sending and receiving. You only need Mailgun if Sparkforge Email is not enabled.
What providers does Sparkforge support?
Sparkforge Email, Mailgun, and standard SMTP providers. Mailgun and Sparkforge Email give the best stats (opens, clicks).
What does the per-email cost get used for?
It is the base value Sparkforge multiplies by your markup to calculate the rebilling charge to sub-accounts.

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