Mailtrap Email API + MCP vs SendLayer

Mailtrap Email API + MCP 93

mailtrap-python v3.0.0 was tagged on 30 October 2026, mailtrap-nodejs v6.0.0 on 29 October, CLI v0.9.0 on 28 October and MCP 0.11.0 on 27 October (30). Since 3 August, MCP 0.7.0 to 0.11.0, Node SDK 4.9.0 to 6.0.0, Python SDK 2.7.0 to 3.0.0 and dated changelog entries up to 16 September (20). Pull requests on the MCP repository are merged within days and Dependabot updates land weekly. A community forum opened on 16 September. Issue reply times weren't visible (18). Listed in the official MCP registry as io.mailtrap/mcp at 0.11.0, published 27 October, and SDKs are current (15). CI runs lint, tests and build on the MCP repository and now on pull requests, with CodeQL on the Node SDK (10).

SendLayer 40

The Node and Python SDKs were last released as 1.1.0 on 21 August 2026, 77 days before this check (20). One SDK release in the 90 days and no dated changelog (0 of 20). A closed service with a support form and docs updated through 2026, but no public changelog (5 of 15). Not in the official MCP registry (search for sendlayer returned nothing on 6 November). Official SDKs in five languages (10 of 15). The SDK repositories exist on GitHub under sendlayer; their CI wasn't read (5 of 10). Total 40.

Mailtrap Email API + MCP 77

Closed service with published terms, and MIT licences on the MCP server, Node SDK and CLI (20). The privacy policy gives retention periods by category (email content and logs within 30 days of a deletion request, account data up to 90 days), and the DPA and sub-processor list agree with it. The policy also allows AI-assisted analysis of email content for abuse prevention (24). No deprecation policy found. The MCP server keeps legacy parameter names, and the terms let Mailtrap modify or discontinue the service with or without notice (4). Twelve sub-processors named with purpose and country, all in the United States, updated 6 October 2026, with data on AWS us-east-1 and Google in the US. EU storage is described as planned (18).

SendLayer 49

Closed service with terms naming SendLayer, LLC under Florida law (15 of 30). The privacy policy is undated, says data is kept as long as the account is active or as needed, and names no retention periods, DPA or processors; only the pricing page gives log retention per plan (8 of 30). No deprecation policy or dated notices (0). No sub-processors or data locations disclosed (0). Total 23.

Mailtrap Email API + MCP 60

API tokens with permissions per resource, an expiry date (365 days by default), a reset with a 12-hour overlap and management through the API. The docs give header authentication only (28). Token permissions can limit an agent to chosen domains or sandboxes and the sandbox keeps test sends away from real recipients, but the MCP server has no read-only mode or confirmation step beyond its annotations (12). Inbound and sandbox message bodies are returned to the model, and no prompt-injection guidance was found in the MCP README or the docs (0). Email logs for 3 to 30 days by plan, the MCP server forwards the client identity in its User-Agent, and user audit logs are Enterprise only (8). ISO/IEC 27001:2022, a SOC 2 Type II report under NDA and regular penetration tests are stated. No security.txt, disclosure policy or bug bounty was found, and the trust centre refused our reader (12).

SendLayer 38

Plain revocable API keys per domain, several allowed, sent in a header; no scopes, expiry or rotation feature beyond creating and deleting keys (20 of 30). No read-only key or approval step (0 of 20). The API returns event data, not received mail (10 of 15). Email logs kept 3, 15 or 30 days by plan, and no log of API calls was found (8 of 15). No security.txt (404), disclosure policy, bug bounty or certification found (0 of 20). Total 38.

Mailtrap Email API + MCP 40

No x402, MPP or L402 (0). Plan prices and overage per 1,000 emails ($1.00, $0.88, $0.55) published without login, including a Markdown pricing page (20). Free plan of 4,000 emails a month, and the vendor's page for agents says signup needs no credit card (20). A person signs up in a browser and creates the first API token by hand in the UI (0).

SendLayer 20

No x402, MPP or L402 (0). Plan prices are public but only as annual plans, with no per-email overage price; accounts are upgraded automatically at the limit (10 of 20). A free trial of 200 emails is offered through checkout; whether it needs a card couldn't be read, since robots.txt disallows the add-to-cart URLs (10 of 20). A person signs up and authorises a domain in a browser (0). Total 20.

Mailtrap Email API + MCP 65

Graded as a hosted service. Status page at status.mailtrap.info with monthly history by component, per the 8 October check (20). On 1 November its robots.txt answered 406 with an empty body, which this run treats as blocked, so the history wasn't re-read. Per the 8 October read, the sending outage of 1 hour 32 minutes on 1 August has left the 90-day window that starts on 3 August, leaving two incidents of about 6 minutes each on Email Testing (the sandbox) on 16 September. The window from 9 October to 1 November is unread and isn't credited, so the line stays at the 8 October award until the history can be read, as merge-accounting's and glean's incident lines were held when their status hosts refused us (10). Rate limits published with numbers, re-read on 1 November, 150 requests per 10 seconds per token and lower per-account limits on Contacts, Stats, Suppressions and Email Logs (15). The docs ask for exponential backoff on 429 and the specs document x-ratelimit-reset, but no idempotency key or safe-retry guidance for sends was found (10). No SLA found in the pricing reference, the terms or the security page (0). The sending API is generally available. The MCP server is at 0.11.0 and Inbound Email has no UI yet (10).

SendLayer 48

Graded with the hosted lines. A Cronitor status page at status.sendlayer.com with components for the app, SMTP, tracking links, the website and each plan's sending IPs, and a history (15 of 20, see below). The 90 days from 8 August hold 98 automated outage entries, 13 of them on SendLayer Services Health, most on per-plan IP monitors, all marked resolved but with no durations or write-ups, so their size can't be judged (5 of 30). Send limits per minute, hour and day are published per plan, plus recipient and size caps (15). 429 appears in the error code list, with no Retry-After, backoff guidance or idempotency for sends (3 of 15). No SLA found (0). The API is at v1 with no beta label (10). The status page's uptime columns showed no data on 6 November, so the component line takes 15 of 20 rather than 20. Total 48.

Mailtrap Email API + MCP 82

Graded on the REST API and the MCP server. Ten public OpenAPI 3.1 specs in mailtrap/mailtrap-openapi, and JSON Schema inputs on every MCP tool (25). llms.txt, llms-full.txt and a Markdown copy of each docs page (10). MCP descriptions are mostly one line. A few say when to use the tool or note a quota, and few say when not to (12). Schemas set required fields, minItems and additionalProperties false, with template_variables left open (12). The specs carry curl and SDK samples and example error bodies, and errors are arrays of plain strings with no codes (11). Specs are versioned 2.0.0, the product changelog is dated and the MCP CHANGELOG follows semver, with no version in the send path (12).

SendLayer 68

OpenAPI file at developers.sendlayer.com/api-reference/sendlayer.json (version 1.0.1) covering four paths, send, events and webhooks (25). llms.txt and Markdown copies of every developer page (10). Operation summaries say what each call does; nothing says when not to use one, and the hosted MCP server's tool definitions aren't public (10 of 20). Parameters are typed but without enums or limits, and the event filter is a free string (7 of 15). Code samples in five languages and a table of 35 error codes, but the spec documents only 200 responses (11 of 15). Version in the path and in the spec, with no public changelog (5 of 15). Total 68.