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Transactional Email

Lettermint

EU-Made Report an error

Panel rating · 6 judges · How to read the stars

Category median

Sovereignty: not determined

0–5 in half steps. 5 means the rubric's top anchor is met on the evidence.

by Lettermint B.V. · lettermint.co

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Add ?theme=dark to the image address for dark backgrounds. The badge shows the category and the month of the latest evaluation, and EU-Made where that is the product’s provenance. It never shows a score.

Lettermint at a glance

Vendor
Lettermint B.V.
Headquarters
Not stated on the vendor’s pages as of 1 Nov 2026
Data hosting
Not stated on the vendor’s pages as of 1 Nov 2026
Free plan
Yes, per the vendor’s own page source, captured 1 Nov 2026
Panel verdict
The AI panel rates Lettermint 3.5/5, the mean of 6 judges. Lettermint is a transactional email API and SMTP relay from Lettermint B.V., a founder-owned Dutch company in Zwolle. how scores are made
As of
Vendor pages captured 1 Nov 2026; evaluated by the panel 1 Nov 2026. all sources

Lettermint alternatives, European ones first →

Read this page as one judge. Each weighs the same scores by what they care about.

The Agency Lead

Weighted verdict

Technical lead at a web agency in Cologne that builds and runs thirty client applications, from a booking portal to a membership site, each sending its own mail from the client's domain. Wants one account with a sub-account, keys and limits per client, domains verified by API, roles so a client can see their own logs and nothing else, and a price per client that can be written into a maintenance contract.

Same scores as the panel view — this lens weights them the way this judge cares.

Scored by The Agency Lead

Panel median The Agency Lead This judge’s scores over the panel median. Each label opens its reasoning below.
Scores per criterion, in stars out of 5
Criterion Panel median The Agency Lead
Sending API, SMTP & developer experience 3.5 of 5 3 of 5
Deliverability & sender reputation 3.5 of 5 3 of 5
Message logs, events & webhooks 3.5 of 5 3.5 of 5
Message data, retention & security 3.5 of 5 3.5 of 5
Reliability, accounts & support 3 of 5 3 of 5
European sovereignty 4.5 of 5 4 of 5
Pricing transparency 2 of 5 1.5 of 5

Sending API, SMTP & developer experience

How this is scored

How an application sends mail: a REST API and an SMTP relay with their limits stated, official SDKs and drivers for named languages and frameworks (PHP and Laravel, Node, Python, Ruby and Rails, Java, Go, .NET), stored templates with variables and versions, batch sending, attachments, idempotency keys, scheduled sending, a test or sandbox mode that does not deliver, inbound email parsed into a webhook, and the quality of the API reference and guides.

0 — Not a sending service; an application cannot send email through it by API or SMTP.

3 — An API or SMTP credentials to send a message; SDKs, templates, limits and a test mode are basic or not described.

5 — A documented REST API and SMTP relay, official SDKs for several named languages, stored templates with variables, attachments and batch sending, rate limits stated, a sandbox or test mode, and quick-start guides for named frameworks.

8 — An API reference with every endpoint and error code, idempotency keys, scheduled sending, template versions and a template language documented, inbound email parsed to a webhook, an OpenAPI specification or official CLI, framework drivers maintained by the vendor, and a migration guide from named competitors.

10 — An API a team builds its product on: versioning and deprecation policy published, backward compatibility stated, full parity between API and SMTP features, local or staging test tooling that mirrors production, and every limit, timeout and retry behaviour documented.

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The Agency Lead

Official SDKs for ten named languages including Laravel, Symfony and.NET, a REST API with a downloadable OpenAPI schema, a CLI and MCP server, sandbox projects with simulated results, scheduled sending on Growth and Pro, and a batch endpoint taking five hundred emails per request cover nearly everything my team touches. We found no public information on stored templates with versions, sending idempotency keys, or a migration guide from the providers I would be moving thirty clients off, which is what keeps this short of the top band. 2 13 14 5 7

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Deliverability & sender reputation

How this is scored

What the vendor does so the mail reaches the inbox: guided SPF, DKIM and DMARC set-up with a custom return path and tracking domain, shared IP pools and how senders on them are vetted and policed, dedicated IPs with automatic warm-up, transactional and bulk mail kept on separate streams or IP pools, bounces, complaints and unsubscribes turned into suppressions automatically, feedback loops with mailbox providers, blocklist and DMARC monitoring, compliance with the Gmail and Yahoo bulk-sender rules, and published delivery times or inbox placement with their method.

0 — No sender authentication and no bounce handling; mail goes out from shared addresses with no reputation management at all.

3 — SPF and DKIM can be set up and bounces are recorded; IP policy, stream separation and suppressions are basic or not described.

5 — Guided SPF, DKIM and DMARC set-up with a custom return path, shared IPs with a stated sender vetting policy, dedicated IPs available, automatic suppression of hard bounces and complaints, transactional and marketing mail separated by stream or IP pool, and deliverability guidance in the documentation.

8 — Dedicated IPs with automatic warm-up and pool management, a stated acceptable-use and vetting process for shared pools, feedback loops and blocklist monitoring, DMARC reports, BIMI or custom tracking domains, compliance with the Gmail and Yahoo sender requirements stated, delivery times published, and access to deliverability experts.

10 — Deliverability that can be verified: delivery time and bounce rates per mailbox provider published continuously with their method, inbox placement testing included, pool reputation shown to the customer, and a documented escalation path with mailbox providers.

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The Agency Lead

SPF handled by a CNAME approach, hosted and rotated DKIM, DMARC required before sending, pre-warmed IP pools with transactional and broadcast kept apart, automatic hard-bounce suppression, spam-score insights and a live Time to Inbox page per mailbox provider are all documented. We found no public information on a vetting policy for senders on the shared pools, feedback loops, DMARC reports, or a statement on the Gmail and Yahoo bulk-sender rules, so I stop below the higher marks. 2 16 1 7 17

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Message logs, events & webhooks

How this is scored

What the team can see about each message once the application has handed it over: a message log searchable by recipient, subject, tag or message ID, the full event history (processed, delivered, deferred, bounced with the remote server's answer, opened, clicked, complained), how long logs and message content are kept, event webhooks with retries and a signature, an events API, dashboards and statistics per stream, tag or domain, alerts on bounce or complaint spikes, and access for a support team without developer rights.

0 — Nothing can be seen after sending; no logs, no events and no webhooks.

3 — Totals of sent and bounced messages; per-message logs, webhooks and retention are basic or not described.

5 — A searchable message log with per-message event history and the bounce reason, log retention stated, event webhooks for delivery, bounce, open, click and complaint, statistics per tag or domain, and an API to fetch events.

8 — Webhooks signed and retried with their schedule documented, the raw SMTP response and the rendered message viewable per send, log retention configurable or extended by plan, alerts on bounce, complaint or delivery-time thresholds, export or streaming of events to a named log or data tool, and read-only roles for support staff.

10 — Full traceability: every message traceable from API call to the receiving server's final answer, events streamed in real time with ordering and delivery guarantees stated, long retention with search across the whole history, and observability features documented with their limits.

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The Agency Lead

Email Activity searches by recipient, subject, tag, project and date range, shows per-recipient events plus the source, HTML and plain text, and the webhook machinery is first class: HMAC-SHA256 signed, twelve attempts across roughly fourteen hours with the schedule published, deliveries listable and retryable, sandbox or live selectable per webhook. Retention is stated at twenty-eight days for messages and fourteen for logs, but we found no public information on configurable or extended retention, bounce or complaint spike alerts, or export to a log tool. 17 5 18 10 7

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Message data, retention & security

How this is scored

What is stored about each message and what the customer controls: whether message bodies are stored or only metadata, retention periods and the setting to shorten them, deletion of a recipient's data on request, open and click tracking that can be switched off per stream or message, TLS for delivery with an option to require it, encryption at rest, API keys with scopes and per-domain restrictions, IP allow-listing, two-factor authentication and SSO for the dashboard, an audit log, a vulnerability disclosure programme, and security certifications or audits with their scope. Where the data is processed and by whom is scored under sovereignty.

0 — Stores every message indefinitely with no controls, and the vendor states it uses message content for its own purposes.

3 — A privacy policy and a statement that data is encrypted; what is stored, retention and access controls are basic or not described.

5 — What is stored per message documented, retention periods stated, open and click tracking switchable, TLS used for delivery, API keys with restricted permissions, two-factor authentication for the dashboard, and a data processing agreement offered.

8 — Message content retention configurable down to none or metadata only, enforced TLS per domain or message, encryption at rest stated, scoped API keys and IP allow-listing, SSO (SAML) and roles, an audit log, deletion of recipient data by API, and ISO 27001 or SOC 2 stated with its scope.

10 — Data minimisation that can be verified: every stored field and its retention listed, content never stored unless the customer opts in, customer-managed encryption keys or equivalent, independent audits published with their scope, and every security control the customer has listed with its effect.

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The Agency Lead

The data processing agreement documents exactly what is held per message for twenty-eight days, encryption at rest and in transit over TLS 1.2 or higher, daily encrypted backups, enforced TLS per route and per email with no fallback, project and team tokens on separate permission systems, IP allow-lists, activity logs, SCIM and an independently audited ISO 27001:2022 certificate in a public trust center. We found no public information on two-factor authentication for the dashboard, SAML single sign-on, or a setting to shorten retention, so I hold it just below the top. 10 19 14 7 11

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Reliability, accounts & support

How this is scored

Whether the platform can be relied on and run by a team: a public status page with incident history, uptime SLA and service credits published, redundancy or failover across data centres described, queueing and retry of mail during outages, sub-accounts or servers per application, client or tenant, team members with roles, separate environments, support channels and response times per plan, named migration help, and integrations with platforms that send mail on the customer's behalf (WordPress, Shopify, Shopware, Supabase, Vercel and similar).

0 — No status page, no support channel and no way to separate users or applications.

3 — A support contact and a single account; status page, SLA, sub-accounts and roles are basic or not described.

5 — A public status page with incident history, an uptime SLA on at least one plan, sub-accounts or separate servers per application, team members with roles, support by email or chat with stated hours, and plugins or guides for several named platforms.

8 — An SLA with service credits published, redundancy across data centres or regions described, mail queued and retried during incidents, sub-accounts with their own keys, domains and limits manageable by API, granular roles, support response times per plan, and migration assistance offered.

10 — Reliability that can be verified: uptime history published for years, post-mortems for incidents, multi-region failover documented, an SLA covering delivery latency as well as API availability, and white-label or reseller tooling for agencies and platforms.

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The Agency Lead

Projects work as the per-client unit I need, each with its own API token, domains, routes, webhooks and an SMTP toggle, and the role model is the best-documented part: custom roles, project-scoped access and delegation limited to your own permissions, so a client can see their own logs and nothing else. We found no public information on a public status page with incident history, service credits, or named migration help, response times appear only as an enterprise SLA, and there is a WordPress plugin plus Zapier and Make but no named support for platforms like Shopify or Shopware. 21 22 7 3 6

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European sovereignty

How this is scored

Who the contracting entity and the parent company are, where messages, logs and recipient data are processed and stored, whether an EU region can be chosen and what it covers, and who the subprocessors are (cloud hosting, sending infrastructure, logging, support and payment tools). Independently sourced by the sovereignty pipeline; every message carries personal data, so the whole sending chain counts, not only the dashboard.

0 — Non-EU vendor and contracting entity, hosting unstated, subprocessors unnamed, and no data processing agreement offered.

3 — A privacy policy and a data processing agreement exist, but hosting location is unstated or non-EU and the subprocessors are not listed.

5 — An EU region available and an EU contracting entity or EU representative, but parts of the chain (sending infrastructure, logs, support, payment) run through non-EU providers without a stated safeguard, or the EU region does not cover logs and account data.

8 — EU processing of messages, logs and account data on named infrastructure, an EU contracting entity, subprocessors listed with their locations, a data processing agreement published, and security certifications (ISO 27001, SOC 2) stated.

10 — Sovereign end to end and evidenced: European ownership, entity, hosting, sending infrastructure and every subprocessor, data export and deletion documented, and certifications published with their scope rather than implied.

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The Agency Lead

Everything I would put in front of a German client's data protection officer is on the record: a Dutch contracting entity in Zwolle, EU-only processing and storage on their own network and infrastructure with encrypted backups in Germany, a published subprocessor list in which only UpCloud, OVH Cloud and Postmastery, all in the EU, handle email, an automatic and countersignable DPA under Dutch law, ISO 27001:2022 and founder ownership with no investors. Deletion of a recipient's data on request and the exact scope of the certification are not shown in that detail, which keeps it off the top mark. 11 3 8 10 1

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Pricing transparency

How this is scored

Whether a buyer can compute the real annual cost from public pages alone: price per tier by monthly message volume, the price per additional thousand messages, the free tier and its limits, what dedicated IPs, extra log retention, sub-accounts, SSO and support plans cost, minimum term, and whether unused volume carries over.

0 — No public prices at all; every customer is a sales call.

3 — A starting price or a free tier exists, but how cost scales with volume or which features cost extra is unclear.

5 — Tiers are public with their monthly volume and price, but at least one commonly needed piece (overage rate, dedicated IP, longer log retention, SSO, support plan) is unpriced or "on request".

8 — Every tier priced publicly with its volume and overage rate per thousand messages, dedicated IPs and add-ons priced, log retention per tier stated, minimum term and VAT treatment stated.

10 — Complete price computability: annual cost derivable for a given monthly volume, number of domains and sub-accounts and feature set, with every add-on, support and overage fee and the cancellation terms published.

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The Agency Lead

The pricing page shows a free tier of three hundred emails a month, unlimited paid volume, euro billing exclusive of VAT, upgrade, downgrade or cancel anytime, SEPA transfer on every plan and a dedicated IP add-on above three hundred thousand emails a month on Pro. We found no public information on the per-tier euro prices themselves, the overage is described only as a small fee and the dedicated IP is unpriced, so I cannot compute a per-client annual cost for a maintenance contract from these pages. 7 8

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European sovereignty — proven facts

0 of 6 dimensions proven

Built only from facts shown on the vendor's own pages. A dimension we could not prove is left open, not scored as zero.

Hosting location Not determined ⚠ unverified — uncited Report an error
Hosting options Not determined — uncited Report an error
Open source Not determined — uncited Report an error
Data processing agreement Not determined ⚠ unverified — uncited Report an error
Transfer impact assessment Not determined — uncited Report an error

Questions about Lettermint

Is Lettermint European?

Yes. whats-best.ai classifies Lettermint as EU-Made.

Where does Lettermint store data?

Not stated on the vendor’s pages as of 1 Nov 2026.

Does Lettermint have a free plan?

Yes. Lettermint has a free plan, per the vendor’s page captured 1 Nov 2026.

What are the best alternatives to Lettermint?

As of 2 Nov 2026, the panel rates Bird Email API (formerly SparkPost) (3/5), Postmark (3/5) and Mailjet Email API (3/5) highest among the other 15 Transactional Email products evaluated. Ratings that look equal are rounded to half stars; the order uses the unrounded rating, then the name. The highest-rated European alternative is Bird Email API (formerly SparkPost) (EU-Made). Ratings are the AI panel’s opinion, formed from public evidence: how scores are made. The full list, with European products first: Lettermint alternatives.

Where this could be wrong

What we left out

A claim that does not survive our checks costs us the claim, not the page. This is what was taken off this one.

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Sources (22)

The pages every claim on this page was read from — each one checked, dated, and kept verifiable.

  1. 1 Vendor homepage lettermint.co Checked 1 Nov 2026 Details →
  2. 2 Features page (transactional email) lettermint.co Checked 1 Nov 2026 Details →
  3. 3 Features page (European email infrastructure) lettermint.co Checked 1 Nov 2026 Details →
  4. 4 API documentation lettermint.co Checked 1 Nov 2026 Details →
  5. 5 Documentation (webhooks) lettermint.co Checked 1 Nov 2026 Details →
  6. 6 Integrations page lettermint.co Checked 1 Nov 2026 Details →
  7. 7 Pricing page lettermint.co Checked 1 Nov 2026 Details →
  8. 8 Terms of service (company details) lettermint.co Checked 1 Nov 2026 Details →
  9. 9 Privacy policy lettermint.co Checked 1 Nov 2026 Details →
  10. 10 Data processing agreement (dpa) lettermint.co Checked 1 Nov 2026 Details →
  11. 11 Subprocessor list lettermint.co Checked 1 Nov 2026 Details →
  12. 12 Security / trust page trust.lettermint.co Checked 1 Nov 2026 Details →
  13. 13 Sending API, SMTP & developer experience — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  14. 14 Sending API, SMTP & developer experience — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  15. 15 Deliverability & sender reputation — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  16. 16 Deliverability & sender reputation — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  17. 17 Message logs, events & webhooks — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  18. 18 Message logs, events & webhooks — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  19. 19 Message data, retention & security — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  20. 20 Message data, retention & security — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  21. 21 Reliability, accounts & support — found from sitemap lettermint.co Checked 1 Nov 2026 Details →
  22. 22 Reliability, accounts & support — found from sitemap lettermint.co Checked 1 Nov 2026 Details →