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Dedicated vs Shared IP Cost Calculator
Compare the total monthly cost of running dedicated PowerMTA infrastructure against per-recipient ESP pricing. Calibrated to 2026 market rates: Mailgun $59/IP, SendGrid $30/IP, Postmark $50/IP, AWS SES $0.10 per 1K emails. Browser-only.
Compare total monthly cost between your current ESP and dedicated sending infrastructure.
What this calculator shows, and what it does not
The output is a direct cost comparison: your current per-thousand ESP rate times your monthly volume, versus the fixed-cost structure of dedicated infrastructure (server + IPs + a small variable add-on for queue and operations overhead). The calculator shows the volume at which the lines cross — the break-even point where dedicated becomes cheaper. It is honest about the simple math.
Two things the calculator does not capture, both of which usually push the decision further toward dedicated than the raw cost would suggest. The first is the deliverability quality factor: shared IP pools share reputation, which means a noisy neighbour on the pool degrades your inbox placement even if you do everything right. Independent tests in 2026 show shared-IP inbox placement at major ESPs averaging 71% (Mailgun) and 61% (SendGrid) on identical content sent through identical authentication. Dedicated infrastructure consistently outperforms by 10-25 percentage points once warmed. That delta is worth real money in any programme where email drives revenue.
The second is the operational complexity factor: dedicated infrastructure requires someone who can warm an IP, monitor reputation, handle blocklist incidents, and tune PowerMTA. If you do not have that person internally, the operational time costs are real — even if they do not show up on the calculator. Senders who underestimate this end up paying twice: once for the infrastructure, once for the deliverability consultancy that comes when something breaks at 2am.
Volume thresholds where the answer changes
Most published "dedicated vs shared" guidance is anchored to the wrong number — the per-email cost ratio — rather than the volume threshold where dedicated infrastructure starts producing better deliverability than shared. The two thresholds matter for different reasons.
| Monthly volume | Cost answer | Deliverability answer |
|---|---|---|
| Under 50K | ESP wins on cost — dedicated infrastructure rarely covers its fixed cost at this volume | Dedicated IP at this volume often produces worse deliverability than a well-managed shared pool, because the IP cannot generate enough engagement to maintain reputation |
| 50K–100K | Roughly even on cost. ESP and dedicated are within $50-100/month of each other | Dedicated becomes viable once volume sustains warming. Mailgun's published threshold for offering dedicated IPs is 50K+/month for this reason |
| 100K–500K | Dedicated wins on cost in most configurations. Annual savings typically $5K-$15K | Dedicated produces measurably better deliverability than shared pools across all major ESPs in independent 2026 tests |
| 500K–1M | Dedicated wins decisively. Mailgun Scale plan ($90 + $59/IP) versus self-hosted PowerMTA ($180-300 total) is a large gap | Stream isolation becomes essential. One IP for transactional, one for marketing, one for cold — impossible economically on per-IP ESP pricing |
| Over 1M | Dedicated is several times cheaper. AWS SES at $0.10/K is the only ESP that competes, and only without the deliverability suite | Custom configuration (per-ISP throttling, vMTA tuning, accounting log analysis) becomes necessary at this volume; ESPs do not expose it |
Cost components the simple calculation misses
The headline cost comparison is base ESP rate vs base dedicated infrastructure. The real comparison includes a list of line items that recur in every actual procurement decision and rarely appear in vendor pricing pages.
Hidden ESP costs
- Overage fees. SendGrid bills at up to $0.00133 per email above plan limits; Mailgun at $0.50-$0.80 per 1K. A volume spike during a successful campaign produces unpredictable bills.
- Dedicated IP add-ons. SendGrid charges $30/IP/month above the base plan; Mailgun $59/IP; Postmark $50/IP. If you need stream separation (transactional + marketing + cold), this multiplies fast.
- Email validation credits. Most ESPs charge $0.001-$0.005 per validation. At 1M sends/month, that is $1K-$5K/month in addition to the send cost — and validation is mandatory for healthy sender reputation.
- Deliverability suite. Mailgun's "Optimize" add-on is $49-99/month. SendGrid's "Premium" support is several thousand. AWS SES's deliverability dashboard is $1,250/month.
- Failed delivery counted as sent. Most ESPs count bounces toward your monthly quota. A list with 5% bounce rate effectively pays for 5% of nothing.
Hidden dedicated infrastructure costs
- Operational time. IP warming, reputation monitoring, blocklist incident response, MTA tuning. Estimate 10-20 hours/month at engineering rates — this is real and recurs.
- PowerMTA license. Commercial MTA licenses range $5K-$30K/year depending on tier. Open-source alternatives (KumoMTA, Postfix) are free but require more engineering attention.
- Datacenter or VPS. A production-grade SMTP server starts around $50-100/month for basic capacity, $200-400/month for the kind of resources high-volume senders actually need.
- IPs themselves. $3-5/month per IP at most datacenters. Negligible at small numbers; meaningful when you operate 20+ IPs across multiple streams and regions.
- Backup and failover. Production email infrastructure typically runs in HA pairs. Doubles the server line item; mostly invisible until you need it.
Three real scenarios
Scenario A: SaaS sending 80K transactional emails/month
Current: Postmark Premium tier, around $295/month base + $50/IP if dedicated. Total around $345/month. Dedicated alternative: $180 server + 1 IP + ops overhead = approximately $230-280/month. The math says dedicated wins by $65-115/month, or $780-$1,380/year. Recommendation: at this volume, the cost gap is real but small, and Postmark's deliverability is already excellent. The migration friction is rarely worth it unless the sender has a strong reason to leave (data residency, custom configuration, multi-stream isolation).
Scenario B: Ecommerce sending 1.2M marketing + 200K transactional/month
Current: SendGrid Pro tier at around $290/month plus $30/IP for 3 IPs (stream separation) = $380. Plus $0.0008 per email overage on the marketing path roughly $400/month. Total ~$780/month, or $9,360/year. Dedicated alternative: $300 server + 6 IPs ($18) + ops overhead = approximately $400-500/month, or $4,800-$6,000/year. Recommendation: dedicated wins decisively. The annual savings cover an extra deliverability headcount, and the stream isolation produces measurably better marketing-side performance because complaint events stay isolated from the transactional path.
Scenario C: B2B SaaS sending 25K/month
Current: SendGrid Essentials at $19.95/month, shared IPs. Dedicated alternative would cost around $200/month minimum including IP and ops. Recommendation: stay on shared. Below 50K/month, a dedicated IP cannot maintain reputation, and the cost premium would be roughly 10x with worse deliverability outcomes. The right next step at this volume is improving authentication (DMARC enforcement) and engagement signals on the existing shared infrastructure, not changing infrastructure.
Common mistakes when running this comparison
- Comparing dedicated raw IP cost to ESP per-IP markup. A raw IP at a datacenter is $3-5/month. The same IP rented from Mailgun is $59. That is a 12-20x markup, and it is the largest hidden cost in the shared-vs-dedicated decision. Most calculators that say "dedicated costs more" are using the ESP markup price, not the actual cost of an IP.
- Ignoring the deliverability quality delta. A 10-percentage-point inbox placement improvement on $100K/month of email-driven revenue is $10K/month in additional revenue. That dwarfs almost every infrastructure cost difference, and most published comparisons leave it out.
- Underestimating operational time on dedicated infrastructure. If your team does not include someone who can warm an IP, monitor Postmaster Tools daily, and handle a Spamhaus listing, dedicated infrastructure has a hidden cost: either you hire that person, or you pay a deliverability consultancy on retainer (typically $500-2K/month).
- Treating one-time migration cost as ongoing cost. ESP-to-dedicated migrations have a real upfront cost (warming period, suppression list import, application changes) but those are amortised once over the lifetime of the infrastructure. Including them in monthly comparison overstates the dedicated cost.
- Forgetting stream separation. Marketing and transactional should run on different IPs. If your ESP charges per dedicated IP and you need both streams isolated, your real ESP cost is 2x the per-IP fee. Dedicated infrastructure makes additional IPs nearly free.