The break-even point between self-hosted and hosted email depends on your ESP, sending volume, and the value of your maintenance time. Against Mailgun, break-even is ~200K emails/month assuming $150/month in time costs. Against SendGrid, it's ~150K/month. Against AWS SES (cheapest ESP), break-even doesn't arrive until 1.5M+ emails/month. The break-even drops significantly if you already have a sysadmin who can absorb maintenance.
Self-Hosted vs. Hosted Email: Finding the Break-Even Point
Break-Even Analysis: When Self-Hosting Pays Off
The self-hosted vs. hosted decision is ultimately a math problem. See our self-hosted cost calculator and self-hosted pros and cons for context. Every month, you're either saving money by self-hosting or paying a premium for the convenience of a managed ESP. The break-even point is where those costs cross.
The Formula
Break-even Volume = (Self-hosted costs) / (ESP per-email rate)
Self-hosted costs = Infrastructure + Time + Monitoring + Risk buffer
ESP costs = Volume x Per-email rate + Fixed fees
Break-Even Against Each ESP
vs. Mailgun
Mailgun charges approximately $0.80/1,000 emails on their Foundation plan.
| Monthly Volume | Mailgun Cost | Self-Hosted Cost (w/ time) | Savings |
|---|---|---|---|
| 50K | $40 | $165 | -$125 (ESP wins) |
| 100K | $80 | $165 | -$85 (ESP wins) |
| 200K | $160 | $165 | -$5 (break-even) |
| 500K | $400 | $175 | +$225 (self-hosted wins) |
| 1M | $800 | $180 | +$620 (self-hosted wins) |
Break-even: ~200K emails/month
vs. SendGrid
SendGrid's Pro plan starts around $90/month for 100K emails, scaling with volume.
| Monthly Volume | SendGrid Cost | Self-Hosted Cost (w/ time) | Savings |
|---|---|---|---|
| 50K | $20 | $165 | -$145 (ESP wins) |
| 100K | $90 | $165 | -$75 (ESP wins) |
| 200K | $180 | $165 | +$15 (self-hosted wins) |
| 500K | $450 | $175 | +$275 (self-hosted wins) |
| 1M | $900+ | $180 | +$720 (self-hosted wins) |
Break-even: ~175K emails/month
vs. Postmark
Postmark charges $1.25/1,000 emails — premium pricing for premium deliverability.
| Monthly Volume | Postmark Cost | Self-Hosted Cost (w/ time) | Savings |
|---|---|---|---|
| 50K | $63 | $165 | -$102 (ESP wins) |
| 100K | $125 | $165 | -$40 (ESP wins) |
| 150K | $188 | $165 | +$23 (self-hosted wins) |
| 500K | $625 | $175 | +$450 (self-hosted wins) |
Break-even: ~135K emails/month
vs. AWS SES
SES is the hardest ESP to beat on cost at $0.10/1,000 emails.
| Monthly Volume | SES Cost | Self-Hosted Cost (w/ time) | Savings |
|---|---|---|---|
| 100K | $10 | $165 | -$155 (ESP wins) |
| 500K | $50 | $175 | -$125 (ESP wins) |
| 1M | $100 | $180 | -$80 (ESP wins) |
| 2M | $200 | $185 | +$15 (break-even) |
| 5M | $500 | $195 | +$305 (self-hosted wins) |
Break-even: ~1.8M emails/month
Factors That Shift Break-Even Lower
These make self-hosting financially viable at lower volumes:
Existing Sysadmin Staff
If your team already has a sysadmin, time cost drops to near-zero:
| Volume | Self-Hosted (no time cost) | Mailgun | SES |
|---|---|---|---|
| 50K | $15 | $40 | $5 |
| 100K | $15 | $80 | $10 |
| 200K | $20 | $160 | $20 |
Break-even against Mailgun drops to ~20K/month. Against SES, ~200K/month.
Multiple Domains
Agencies running 10-50 client domains pay per domain on most ESPs. Self-hosted handles unlimited domains on the same server.
Example: 10 domains sending 20K each = 200K total
- Mailgun: 10 domains with separate billing = $160+/month
- Self-hosted: same $15/month regardless
Data Residency Requirements
If GDPR or compliance requires EU data hosting, self-hosted on a Hetzner server in Germany may be cheaper than EU-region ESP plans with compliance add-ons.
Factors That Shift Break-Even Higher
These make ESPs financially viable at higher volumes:
Expensive Engineering Time
If your hourly rate is $200/hour, 2 hours/month = $400 in time costs:
Break-even vs. Mailgun: ($415) / $0.0008 = 519K/month
Break-even vs. SES: ($415) / $0.0001 = 4.15M/month
Frequent Incidents
If your server requires 6-8 hours/month of troubleshooting instead of 2:
Time cost: 8 hours x $100/hour = $800/month
Break-even vs. Mailgun: ($815) / $0.0008 = 1.02M/month
Opportunity Cost of Downtime
If email drives significant revenue, factor in expected downtime costs: 1-2 incidents per year x revenue impact per hour.
The Decision Matrix
| Your Situation | Recommendation |
|---|---|
| Under 50K/month, no sysadmin | Stay with ESP |
| 50K-200K/month, technical team | Evaluate case-by-case |
| 200K-500K/month | Self-hosted likely wins |
| 500K+/month | Self-hosted almost certainly wins |
| Any volume, existing sysadmin | Self-hosted likely wins |
| Multiple domains/agency | Self-hosted wins earlier |
| Non-technical team, any volume | Stay with ESP or hire managed |
Practitioner note: The break-even analysis only tells half the story. Some of my clients self-host at 100K/month — well below the financial break-even — because they need control over their sending infrastructure that no ESP provides. The break-even calculation assumes the only value is cost savings. Control, independence, and data ownership have value too.
Practitioner note: The biggest mistake in break-even analysis is assuming maintenance time stays constant. A new self-hosted server demands 4-8 hours in month one. By month six, it's 1-2 hours. Use the stabilized time cost (months 3+), not the setup phase, for your ongoing calculation.
If you want a personalized break-even analysis for your specific sending patterns and ESP costs, schedule a consultation — I'll model the numbers and recommend the optimal infrastructure.
Sources
- Mailgun: Pricing
- SendGrid: Pricing
- Postmark: Pricing
- AWS SES: Pricing
- Hetzner: Cloud Pricing
v1.0 · April 2026
Frequently Asked Questions
What's the fastest way to calculate my break-even?
Take your current monthly ESP bill, subtract your projected self-hosted costs ($10-40/month infrastructure + maintenance hours x hourly rate). If the result is positive, you're past break-even. If negative, you're better off with the ESP.
Does the break-even change with multiple domains?
Yes, in favor of self-hosted. ESPs charge per sending domain or per email regardless of domains. Self-hosted costs the same whether you run 1 domain or 50 domains. Agencies with many client domains reach break-even at lower per-domain volumes.
What if I already have a sysadmin on staff?
The break-even drops dramatically because time cost approaches zero (the sysadmin is already paid). If your sysadmin can absorb mail server maintenance into their existing workload, break-even can be as low as 50K emails/month.
How do I account for downtime costs?
Estimate the revenue impact of email being down for 1-4 hours (typical self-hosted incident). If your email generates $1,000/day in revenue, a 4-hour outage costs ~$167. Factor 1-2 incidents per year into your annual calculation.
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