# Lettermint — Transactional Email Lettermint by Lettermint B.V. holds a panel rating of 3.5/5 from 6 AI judges (category median 3/5), as of 2026-11-01. Provenance: EU-Made; sovereignty: not determined. - Vendor: Lettermint B.V. (https://lettermint.co) - Category: [Transactional Email](https://whats-best.ai/software/transactional-email.md) - Provenance (editorial classification): EU-Made - Canonical page: https://whats-best.ai/software/transactional-email/lettermint - Alternatives: https://whats-best.ai/software/transactional-email/lettermint/alternatives ([markdown](https://whats-best.ai/software/transactional-email/lettermint/alternatives.md)) - Data as of: 2026-11-06 · evaluated 2026-11-01 · oldest source captured 2026-11-01 **AI-generated.** Every score, rationale and verdict here is written by a panel of AI judges from public evidence — an analysis, not a hands-on test. Every fact quotes the vendor page it was read from. No score can be bought. How scores are made: https://whats-best.ai/methodology ## 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 [S2] ## The panel's verdict Lettermint is a transactional email API and SMTP relay from Lettermint B.V., a founder-owned Dutch company in Zwolle. Its strongest dimension is sovereignty, scored 8-9: EU-only hosting, storage and processing on the vendor's own infrastructure and network, a subprocessor list naming only UpCloud and Postmastery in the Netherlands and OVH Cloud in Germany as handling email, an automatically applicable Article 28 GDPR data processing agreement, and independently audited ISO/IEC 27001:2022 certification. Data and security follows at 7-8, observability at 7, sending API and deliverability at 6-7. The weakest is pricing transparency at 3-4: the captured pricing page shows the free tier's 300 monthly emails but no euro prices for paid plans, an overage described only as "a small fee", and an unpriced dedicated IP add-on, so annual cost cannot be computed from public pages. Reliability and accounts sits at 5-6: no public status page or incident history was found, and a written SLA appears only for enterprise customers on Pro. flagged splits registered none; score spreads run at most a single point. **Speaks for it:** - EU-only hosting, storage and processing on the vendor's own infrastructure and network, with every subprocessor listed by role, location and email access - An Article 28 GDPR data processing agreement applies automatically, is countersigned on request, and gives thirty days' notice with objection rights before subprocessor changes - Retention is stated with hard numbers — 28 days for message content and events, no more than 14 for logs, 90 for analytics events - Sending is documented across a REST API with downloadable OpenAPI schema, an SMTP relay with every port and authentication mechanism, official SDKs, batch sending up to 500 emails per request and sandbox projects - Webhooks are HMAC-SHA256 signed with a published retry schedule of twelve attempts over roughly fourteen hours and manual retry from the dashboard **Held against it:** - No euro price for any paid plan appears on the captured pricing pages, and the overage is described only as a small fee - We found no public information on a status page with incident history or on service credits - A written service level agreement with uptime and response-time guarantees exists only for enterprise customers on the Pro plan - We found no public information on two-factor authentication or SAML single sign-on for the dashboard - Message history is fixed at 28 days on every plan, and we found no public information on configuring or extending that retention **Best for:** - You need transactional email with EU-only hosting, storage and processing on the vendor's own infrastructure, documented for a data-protection review - You must hand your data protection officer a countersigned Article 28 GDPR data processing agreement and a published subprocessor list - You need to answer did-it-arrive questions yourself — a searchable message log, per-message event timelines, message content and HMAC-signed webhooks with a documented retry schedule - You send from PHP, Laravel or Symfony and want SMTP and a REST API documented down to ports and authentication mechanisms **Avoid if:** - You must compute a real annual cost from published prices before committing — the captured pricing pages give no euro amounts for paid tiers and describe the overage only as a small fee - You need a written uptime and response-time SLA outside an enterprise contract — the written SLA exists only for enterprise customers on the Pro plan - You need more than 28 days of message history — retention is fixed at 28 days on every plan - You need to invite colleagues on the free Developer plan, which seats one user until you upgrade ## Scores by judge and criterion Scores out of 5, each judge scoring independently against the published rubric (v1). "n/r" = not rated: the vendor publishes no price, or the judge found no public information on that criterion. | Criterion | The SaaS Developer | The Platform Engineer | The Shop Operator | The Data Protection Officer | The Agency Lead | The Skeptic | | --- | --- | --- | --- | --- | --- | --- | | Sending API, SMTP & developer experience | 3.5/5 | 3.5/5 | 3/5 | 3.5/5 | 3/5 | 3.5/5 | | Deliverability & sender reputation | 3.5/5 | 3.5/5 | 3.5/5 | 3.5/5 | 3/5 | 3.5/5 | | Message logs, events & webhooks | 3.5/5 | 3.5/5 | 3.5/5 | 3.5/5 | 3.5/5 | 3.5/5 | | Message data, retention & security | 4/5 | 3.5/5 | 3.5/5 | 3.5/5 | 3.5/5 | 3.5/5 | | Reliability, accounts & support | 2.5/5 | 2.5/5 | 3/5 | 3/5 | 3/5 | 3/5 | | European sovereignty | 4.5/5 | 4.5/5 | 4.5/5 | 4.5/5 | 4/5 | 4/5 | | Pricing transparency | 2/5 | 2/5 | 2/5 | 2/5 | 1.5/5 | 2/5 | | **Weighted verdict** | **3.5/5** | **3.5/5** | **3.5/5** | **3.5/5** | **3/5** | **3.5/5** | ### The judges - **The SaaS Developer** (v1.0): Backend developer at a twelve-person B2B SaaS in Hamburg, built on Laravel, that sends sign-up confirmations, password resets, invoices and weekly digests to 40,000 users. Has replaced the mail driver once already and does not want to again. Wants an official driver for the framework, templates with variables, a test mode that never reaches a real inbox, signed webhooks for bounces, and a log that answers "did this user get the reset mail?" without opening a ticket. - **The Platform Engineer** (v1.0): Platform engineer at a fintech in Frankfurt whose customers sign in with a one-time code sent by email, so a delay of three minutes is an outage. Is on call for it. Reads the status page history before the feature list, wants the SLA in writing with credits, mail queued and retried during an incident, delivery latency per mailbox provider, alerts on bounce spikes, and scoped API keys that can be rotated without a deploy. - **The Shop Operator** (v1.0): Runs a Shopware shop for kitchen equipment in Germany and Austria with 900 orders a week. Order confirmations, invoices and shipping notices went out through the hosting provider's mail server until a customer found theirs in spam and the support inbox filled up. Wants guided SPF and DKIM set-up a non-specialist can follow, a plugin for the shop, order mail kept apart from the newsletter, and someone to ask when Gmail starts refusing. - **The Data Protection Officer** (v1.0): In-house data protection officer at a health software company whose appointment reminders and lab-result notices carry patients' names. Treats the sending service as a processor like any other. Reads the DPA, the subprocessor list and the retention section first: whether message bodies are stored and for how long, whether open tracking can be turned off, which entity signs, and whether the EU region covers the logs as well as the mail. - **The Agency Lead** (v1.0): 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. - **The Skeptic** (v1.0): Has seen "99% deliverability" with no method behind it, "dedicated IPs" that shared a pool with bulk senders, "EU hosting" that covered the API endpoint but not the logs, and seven days of log retention discovered during an incident on day eight. Reads that a vendor is "trusted by thousands of developers" and asks how bounces are suppressed, what is stored per message, which entity signs the DPA — and what moving away would cost. ## European sovereignty — proven facts Built only from facts on the vendor's own pages; a dimension we could not prove is left open, never scored as zero. Headline: not determined. | Dimension | Finding | Points | Source | |---|---|---|---| | Legal entity | Not determined | — | — | | Hosting location | Not determined | — | — | | Hosting options | Not determined | — | — | | Open source | Not determined | — | — | | Data processing agreement | Not determined | — | — | | Transfer impact assessment | Not determined | — | — | ## Key facts Each fact is the vendor's own statement, cited to the source page it was read from ([S*n*] → Sources). **Compliance** - AI human review: yes [S10] - Backup encryption: yes · at least daily [S10] - Breach notification: 24 [S10] - DPA: yes · yes · yes [S7] - DPA amendment notice: 30 · yes [S10] - DPA automatic: yes [S10] - DPA on request: yes [S11] - DPA subprocessors: yes · yes [S3] - Encryption: 1.2 · yes [S10] - EU data only: EUR · yes [S7] - GDPR: yes [S3] - International transfers safeguards: yes · yes · yes [S11] - ISO 27001: yes [S3] - ISO 27001: yes [S11] - ISO 27001: yes [S1] - No data sale: no · no [S10] - No US trackers AI training: no · no [S3] - Public authority requests: yes · yes [S10] - Security questionnaires: enterprise · yes · yes [S7] - Signed DPA available: request form · yes [S10] - Subprocessor notice: 30 · yes [S10] - Subprocessor stripe payments: payment processing · no · Stripe [S10] - Trust center: trust.lettermint.co [S11] - Trust center: yes [S15] **Data** - Analytics retention: 90 · delivery and engagement events for analytics [S10] - Export format: yes [S10] - Log retention: 14 [S11] - Message retention: 28 · message content, attachments, recipient addresses, message metadata, message events [S10] - Retrieval period: 30 [S10] **Hosting** - Autonomous as: AS213427 · yes [S3] - Data storage: encrypted, separate provider in Germany · EU only [S3] - EU infrastructure: yes [S2] - EU infrastructure: yes · yes · yes [S7] - EU processing: Europe · EU [S3] - EU processing: yes [S11] - Made in europe: Made in Europe [S15] - No cloud act: no [S3] - Own network asn: AS213427 · no [S2] - Servers EU only: European only · multiple · no [S3] **Integrations** - API base URL: https://api.lettermint.co/v1 [S13] - API docs: yes [S15] - API smtp sdks: yes · yes · yes [S2] - API surfaces: Sending API and Team API [S4] - Cli: yes [S4] - Cli: yes [S15] - Cli available: Sending API · Team API · MCP server · CLI · yes [S14] - Cli mcp: yes · yes [S2] - Count: 30 [S1] - Mcp server: yes [S4] - Mcp server: yes [S15] - More coming: More integrations announced as coming [S6] - Openapi playground: yes [S4] - Openapi schema download: yes [S13] - Sdk cli mcp: yes · yes · yes [S1] - Sdk languages: Node.js · PHP · Laravel · Symfony · Python · Go · Java · .NET · Rust · Elixir [S2] - Sdks official: SMTP · REST API · CLI · MCP server · Terraform provider · Zapier · Make · Node.js · PHP · Python · Go · Java · .NET · Rust · Elixir [S6] - Sending API tls setting: settings.tls · yes [S19] - Smtp: yes [S15] - Surface: API · SMTP · Webhooks · CLI · MCP Server [S3] - Team API message endpoints: GET /v1/messages · GET /v1/messages/{messageId} · GET /v1/messages/{messageId}/events · GET /v1/messages/{messageId}/source · GET /v1/messages/{messageId}/html · GET /v1/messages/{messageId}/text · yes [S17] - Team API route update: lettermint.routes.update · settings.tls [S19] - Team API scope: read:messages [S17] - Webhook API endpoints: POST /v1/webhooks · PUT /v1/webhooks/{webhook_id} [S5] - Webhook auth bearer: Bearer token [S18] - Webhook auto disable: 72 [S5] - Webhook base URL: /webhooks · https://api.lettermint.co/v1 [S18] - Webhook basic auth: yes [S5] - Webhook basic auth: yes [S18] - Webhook credentials encrypted: no · yes [S5] - Webhook delete deletes delivery records: yes [S18] - Webhook deliveries API: GET /webhooks/{webhookId}/deliveries [S18] - Webhook delivery mode filter: live · sandbox · both [S18] - Webhook delivery modes: Live · Live · Sandbox · both [S5] - Webhook delivery retry: yes · POST /webhooks/{webhookId}/deliveries/{deliveryId}/retry [S18] - Webhook delivery statuses: pending · success · failed · client_error · server_error · timeout [S18] - Webhook events: message.created · message.sent · message.delivered · message.auto_replied · message.hard_bounced · message.soft_bounced · message.spam_complaint · message.failed · 22 (show 14 more) [S18] - Webhook https required: yes · no · no [S5] - Webhook idempotency: event.id [S5] - Webhook machine events option: no · message.opened · message.clicked [S5] - Webhook machine events option: no [S18] - Webhook manual retry: dashboard · Webhook API · MCP · yes [S5] - Webhook multiple webhooks: yes [S5] - Webhook next retry at: yes [S18] - Webhook no redelivery when disabled: no [S5] - Webhook pagination: yes · 15 [S18] **Legal** - Company name: Lettermint B.V. [S6] - DPA: yes [S15] - DPA contact: legal@lettermint.co [S10] - Entity: Lettermint B.V. · yes [S2] - Entity: Lettermint B.V. [S1] - Entity: Lettermint B.V. · Netherlands · no [S3] - Entity: Europe · Lettermint B.V. [S7] - Entity: Lettermint B.V. [S11] - Entity: Lettermint® B.V. [S15] - Entity: Lettermint B.V. · Willemsvaart 16 B, 8019 AB Zwolle, the Netherlands · 99337711 [S10] - Governing law: Netherlands [S8] - Governing law: Netherlands law governs the DPA [S10] - Jurisdiction: District Court of Overijssel location Zwolle (the Netherlands) · users domiciled or established in an EU country, Denmark, Iceland, Norway or Switzerland [S8] - Legal entity: Lettermint B.V. · Willemsvaart 16 B, 8019 AB Zwolle, The Netherlands · Netherlands · 99337711 [S8] - Ownership: no · yes · yes [S3] **Pricing** - Contract flexibility: yes · yes · yes [S1] - Currency and VAT: EUR · no [S8] - Dedicated ip addon: Pro · yes · 300000 [S2] - Dedicated ip byoip enterprise: enterprise only · available as add-on [S7] - Developer plan no team members: no [S22] - Free plan limit: no limit · 300 [S7] - Free tier: yes [S15] - High volume plans: yes · 1500000 [S7] - Invoice payment: yes · yes [S7] - No credit card: yes · no [S7] - Overage fee: additional emails available for a fee when monthly limit exceeded [S7] - Shared volume: yes [S1] - Student startup credit: one-time €60 credit = 6 months Starter for students and startups [S7] **Product** - Admin role permissions: Admin · All delegable permissions; project access can include all projects or a selected set [S21] - AI usage: support-ticket triage · drafting · abuse detection and handling [S10] - Analytics: yes · yes [S1] - Analytics: yes [S4] - Analytics features: Delivery Insights, Tags, Open Tracking, Click Tracking, Custom Tracking Domains, Spam Insights, Weekly reports; some gated by plan [S7] - Auto read permissions: yes [S21] - Backup location: encrypted, in Germany · yes [S2] - Batch endpoint: no · 500 [S7] - Bot opens ignored: yes [S17] - Custom roles: Manage team → Roles · yes [S21] - Dashboard insights: delivery statuses · bounces · yes [S2] - Dashboard only roles: dashboard · yes [S21] - Delegation rules: Delegation limited to permissions and projects the actor possesses; cannot change own role via standard flow [S21] - Delegation within own access: yes [S22] - Deliverability insights checks: missing plaintext · large bodies · suspicious links · missing unsubscribe handling · sender/domain issues [S17] - Deliverability ip pools: yes · yes [S1] - Deliverability kb scope: Knowledge base section covering SPF, DKIM, DMARC, bounces, statuses, blacklists, greylisting and Policy Rejected errors [S15] - Developer surfaces: Sending API · Team API · MCP server · CLI [S13] - Developer tools: SMTP Relay · REST API · Batch sending · SDKs · CLI · MCP · Webhooks · Bounce notifications (DSN) [S7] - Dkim management: yes · yes · yes · yes [S2] - Dmarc default relaxed alignment: Default DMARC aspf is relaxed; SPF alignment passes [S16] - Enforced tls: per route · yes [S2] - Free tier: yes [S2] - Free tier: yes [S3] - Header metadata: X-LM-Metadata- · yes · yes [S14] - Header preserve message id: X-LM-Preserve-Message-ID · yes [S14] - Header route: X-Lettermint-Route [S14] - Header sandbox result: Sandbox result simulation via X-Lettermint-Sandbox-Result header; rejected for Live projects [S14] - Header scheduling: Growth · Pro · X-LM-Scheduled-At · yes [S14] - Header tag: X-LM-Tag · 255 [S14] - Header tags limit: X-LM-Tags · 20 [S14] - Header tags size limits: 32 · 64 · 900 [S14] - Header tls override: X-LM-Override-TLS · enforced · opportunistic [S14] - Hide email content: per project or per route · yes [S2] - Inbound email: yes [S4] - Managed dkim: Managed DKIM and automatic key rotation [S15] - Member removal immediate: yes [S22] - Member role permissions: Member · Standard permissions for projects, routes, domains, messages, and suppressions [S21] - Message details: message details include status, sender/recipients, project/route/tag, event timeline, webhook events, bounce/complaint/suppression/failure metadata, and source/HTML/plain-text content [S17] - Message history: 28 [S7] - Message search filters: search messages by sender, recipient, subject, status, project, route, tag, or date range [S17] - Modules: Transactional Emails · Broadcast Emails · Inbound Emails [S3] - Multi recipient status ranking: spam_complaint · hard_bounced · failed · clicked · opened · delivered · soft_bounced [S17] - Multiple providers supported: Multiple email providers supported via distinct Return-Path subdomains [S16] - New invite default: Member · all projects [S22] **Subprocessors** - Aikido: Security · Europe · no [S11] - Change notice: 30 [S11] - Listed: yes [S2] - Mistral: AI inference · Europe · no [S11] - Objection window: 30 [S11] - Ovh cloud: Cloud provider · Germany · yes [S11] - Page: yes [S15] - Postmastery: Cloud monitoring · Netherlands · yes [S11] - Upcloud: Cloud provider · Netherlands · yes [S11] **Support** - Channels: Ticket Support · Email Support · Social Media Support · Discord Support · enterprise [S7] - Dns propagation time: DNS propagation up to 48 hours, usually minutes [S16] - Enterprise SLA: enterprise customers on Pro · yes [S7] - EU based team: yes [S3] - Response codes documented: 4xx temporary, 5xx permanent SMTP reply codes documented [S14] - Testing tool swaks: swaks recommended as SMTP testing tool [S14] 86 more facts on the canonical page: https://whats-best.ai/software/transactional-email/lettermint ## Questions ### 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](https://whats-best.ai/evidence/14184). ### What are the best alternatives to Lettermint? As of 2 Nov 2026, the panel rates [Bird Email API (formerly SparkPost) (3/5)](https://whats-best.ai/software/transactional-email/bird-email-api), [Postmark (3/5)](https://whats-best.ai/software/transactional-email/postmark) and [Mailjet Email API (3/5)](https://whats-best.ai/software/transactional-email/mailjet-email-api) 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)](https://whats-best.ai/software/transactional-email/bird-email-api) (EU-Made). Ratings are the AI panel’s opinion, formed from public evidence: [how scores are made](https://whats-best.ai/methodology#ordering). The full list, with European products first: [Lettermint alternatives](https://whats-best.ai/software/transactional-email/lettermint/alternatives). ## Head-to-head - [Lettermint vs Postmark](https://whats-best.ai/compare/lettermint-vs-postmark.md) ## What this page leaves out - 36 integrations facts could not be confirmed on the vendor’s page as captured and were left out of this page and of the panel’s material. - 14 pricing facts could not be confirmed on the vendor’s page as captured and were left out of this page and of the panel’s material. - 13 product facts could not be confirmed on the vendor’s page as captured and were left out of this page and of the panel’s material. - 7 compliance facts could not be confirmed on the vendor’s page as captured and were left out of this page and of the panel’s material. - 2 hosting facts could not be confirmed on the vendor’s page as captured and were left out of this page and of the panel’s material. - 2 legal facts could not be confirmed on the vendor’s page as captured and were left out of this page and of the panel’s material. - 2 support facts could not be confirmed on the vendor’s page as captured and were left out of this page and of the panel’s material. - 1 data fact could not be confirmed on the vendor’s page as captured and was left out of this page and of the panel’s material. - 3 sovereignty dimensions could not be confirmed on the vendor’s own pages and are shown as unknown. - 6 of the readings below were written against an earlier fact sheet — a fact has been corrected, added or pulled since. Until the panel next runs on this product you are reading the older judgement. ## Sources - [S1] Vendor homepage: https://lettermint.co/ (checked 2026-11-01) - [S2] Features page (transactional email): https://lettermint.co/features/transactional-emails (checked 2026-11-01) - [S3] Features page (European email infrastructure): https://lettermint.co/european-email (checked 2026-11-01) - [S4] API documentation: https://lettermint.co/docs/api-reference/introduction (checked 2026-11-01) - [S5] Documentation (webhooks): https://lettermint.co/docs/platform/webhooks/introduction (checked 2026-11-01) - [S6] Integrations page: https://lettermint.co/integrations (checked 2026-11-01) - [S7] Pricing page: https://lettermint.co/pricing (checked 2026-11-01) - [S8] Terms of service (company details): https://lettermint.co/terms-of-service (checked 2026-11-01) - [S9] Privacy policy: https://lettermint.co/privacy-policy (checked 2026-11-01) - [S10] Data processing agreement (dpa): https://lettermint.co/dpa (checked 2026-11-01) - [S11] Subprocessor list: https://lettermint.co/subprocessors (checked 2026-11-01) - [S12] Security / trust page: https://trust.lettermint.co/ (checked 2026-11-01) - [S13] Sending API, SMTP & developer experience — found from sitemap: https://lettermint.co/docs/api-reference/sending (checked 2026-11-01) - [S14] Sending API, SMTP & developer experience — found from sitemap: https://lettermint.co/docs/guides/send-email-with-smtp (checked 2026-11-01) - [S15] Deliverability & sender reputation — found from sitemap: https://lettermint.co/knowledge-base/deliverability (checked 2026-11-01) - [S16] Deliverability & sender reputation — found from sitemap: https://lettermint.co/docs/platform/domains/spf (checked 2026-11-01) - [S17] Message logs, events & webhooks — found from sitemap: https://lettermint.co/docs/platform/emails/activity (checked 2026-11-01) - [S18] Message logs, events & webhooks — found from sitemap: https://lettermint.co/docs/api-reference/team/webhook (checked 2026-11-01) - [S19] Message data, retention & security — found from sitemap: https://lettermint.co/docs/platform/emails/tls (checked 2026-11-01) - [S20] Message data, retention & security — found from sitemap: https://lettermint.co/docs/platform/emails/data-retention (checked 2026-11-01) - [S21] Reliability, accounts & support — found from sitemap: https://lettermint.co/docs/platform/teams/roles (checked 2026-11-01) - [S22] Reliability, accounts & support — found from sitemap: https://lettermint.co/docs/platform/teams/team-members (checked 2026-11-01) --- Cite as: whats-best.ai, "Lettermint — Transactional Email", AI panel analysis, as of 2026-11-06. https://whats-best.ai/software/transactional-email/lettermint Corrections: https://whats-best.ai/correct/1271?target=page