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Mailgun's pricing has the most predictable shape in this category. That is exactly what makes it expensive at the wrong volume points. Three tiers. Foundation, Growth, Scale, each with a fixed monthly subscription plus per-message charges above the included quota. The walls between tiers are sharp in a way that competitors disguise better. Foundation tops out at 50,000 messages monthly, no exceptions. Cross 50,001 and you are paying €35 minimum on Growth, regardless of how few messages you actually sent that month. Cross 100,000 and the per-message overage starts compounding aggressively at the Growth tier rate. Cross 1 million and the Scale plan minimum jumps to €90 per month with steeper per-message rates above the included quota of 100,000. The chart below maps where the walls land.

Three lines on the chart. Mailgun's published price scales cleanly inside each tier and then jumps at the wall. Our price scales linearly. We do not have those walls. The third line is the interesting one — Mailgun all-in, including dedicated IP rental at €60 per month each, which most senders need above 500k but Mailgun does not include in the headline figure. The crossings are not where the marketing pages would have you believe. We are cheaper at every volume above 100k, and the gap widens at each Mailgun tier wall — at 200k, at 500k, at 1M, at 5M. The shape of the curve is the answer, not the single price quote at one volume point.

Mailgun pricing is rational up to roughly 100,000 monthly messages and increasingly punishing above that. The €35 Foundation tier is genuinely cheap. The €35 Growth minimum is fine until per-message charges accumulate. The €90 Scale minimum starts looking different once dedicated IPs and TAM engagement are added on top of the base subscription. Procurement teams who build the first-year budget around the headline plan minimum land in trouble at month four, when the actual invoices arrive and the real cost shape becomes visible to finance. We have read enough Mailgun invoices to know the pattern. It is not subtle. The pattern is structural to how Mailgun chose to price the product, and that is not changing without a pricing reset that the company has shown no signs of running. So the math compounds, the procurement team takes the loss, and at month nine someone starts making the migration phone calls.

The jurisdictional question is more complex with Mailgun than with SendGrid. Sinch acquired Mailgun in October 2021. Sinch is a publicly traded Swedish company. The acquisition matters for EU senders evaluating data sovereignty in 2026 because Sweden is in the EU but Mailgun's operating infrastructure remains largely in the United States. The combination produces a corporate structure where the parent is EU-based and the operating entity is not. For most clients this is a non-issue. For clients in regulated EU sectors it is a question procurement increasingly asks during vendor review. The answer is more nuanced than "we are owned by a Swedish parent" suggests, and procurement teams that read past the headline notice.

Three jurisdictional layers apply. The contract counterparty is typically Sinch Email Inc., a Delaware-domiciled subsidiary of Sinch AB. The operating infrastructure runs primarily on AWS in US regions, with EU-region availability described as optional and subject to data residency configuration the customer must explicitly request and verify post-onboarding. The parent company is subject to Swedish corporate law and EU GDPR. The operating subsidiary is subject to US law including the CLOUD Act. EU customers signing with Sinch Email Inc. are signing with a US entity, with appended SCCs and a parent-company commitment to GDPR principles that does not flow down to the operating entity automatically. The question for procurement is whether that combination satisfies their specific compliance regime. The answer varies. It depends on the sector and on the regulator's appetite for parent-company representations versus operating-entity facts.

Our comparison position on this dimension is structurally simpler. BIG BOX Hosting is a Slovenian d.o.o. with operating infrastructure entirely in the EU and Switzerland. There is no US-domiciled subsidiary in the path between the customer contract and the data. There is no CLOUD Act exposure. The simplicity is not a virtue we engineered to win marketing arguments — it is the consequence of being founded in Ljubljana in 2002 and never expanding into the US market for regulatory reasons explained in the founder's note. For senders to whom this matters, the comparison is not Mailgun versus us on a feature checklist. It is whether the corporate structure of the vendor matches the regulatory profile of the buyer. For senders to whom it does not matter, the rest of the matrix decides.

The application change is small. Mailgun's HTTP API and SMTP endpoint both have direct equivalents on our side. For Mailgun SDK users, we publish a thin compatibility shim at github.com/bigbox-lu/mailgun-compat that lets the existing Mailgun SDK calls continue working against our endpoint with a credentials swap. SMTP submission is a host change and a credentials change — most teams cut over the application in under an hour.

The reputation transfer follows the same pattern as any migration. Domain reputation transfers; IP-level reputation does not. The new dedicated IPs warm on a 4-6 week curve starting with your most-engaged segment. Suppression list (bounces, unsubscribes, complaints) gets pulled from Mailgun's API on day one and loaded into our infrastructure before any traffic flows. This step is non-negotiable; the most common migration failure across all providers is re-mailing hard-bounce addresses on the new IPs and burning the new reputation immediately.

Mailgun-specific note: their Email Validation service is a separate product that some teams use to verify list quality before sending. We do not offer email validation as a standalone product, and we do not bundle it. For clients who depend on it, we recommend continuing to use Mailgun Validate (or a third-party verifier like NeverBounce or ZeroBounce or Kickbox) as an external service while migrating the sending infrastructure away. The two responsibilities are genuinely separable; we are the delivery layer, the validation layer is a different conversation.

The traffic cutover runs the same way as any other migration we run — parallel pipelines, 10% increments, daily monitoring of per-domain placement at Gmail/Microsoft/Yahoo/Apple, hold-and-investigate at any percentage where the numbers look worse than they did on Mailgun. Most cutovers complete in 4 weeks; complex multi-domain configurations stretch to 6-8.

The matrix below tries to do what most vendor comparisons do not — show the cells where we admit we lose. Mailgun has genuine technical depth in three areas where we either do not compete or compete differently: their Email Validation API, their Inbound Routes parsing maturity, and the dedicated TAM relationship at higher tiers. The cells where we win are also visible. Read the rows where we lose first. That is what tells you whether the migration makes sense for your specific use of Mailgun, because the things you are using Mailgun for are not the things the marketing page leads with.

Three things we do not have that Mailgun does. You might genuinely need them. The first is Email Validation API — Mailgun's address validation service is mature, well-trained, and integrates cleanly with their pricing. We do not offer this as a product. We tell prospects to use ZeroBounce or Briteverify if list hygiene at scale is the deliverable they need. The second is Inbound Routes. Mailgun's inbound message parsing is the most mature in this category and powers a lot of integrations that depend on email-as-an-API. We do basic inbound. We do not ship the deep regex parsing tooling Mailgun does. The third is the dedicated TAM relationship at higher tiers, which is a real product, well-regarded by clients who use it. Our equivalent is structured differently — engineers reading tickets directly with no triage queue — but it is not the same as a named TAM with quarterly business reviews. If any of those three are deal-breakers, Mailgun is the right answer and we will say so during the discovery call.