Clawpost vs Mailows

Clawpost 42

One shared secret for REST and MCP, compared in constant time, with no scopes, expiry or per-client keys (10 of 30). Sender approval, drafts, and an optional allowlist of domains for routing changes limit what an agent can see and change; the key can still send to anyone (14 of 20). Mail from unapproved senders is hidden from all query tools by default, and list_pending returns metadata without bodies, documented as a prompt-injection guard (15). No log of API or tool calls beyond the stored messages (3 of 15). No security policy, advisories or disclosure route for this personal project (0). Total 42.

Mailows 75

REST keys are tenant-wide or bound to one mailbox, with inbox and send scopes, optional Ed25519 device binding and owner-started rotation after 2FA with an atomic cutover. The OpenAPI file says never to put a key in a query string. MCP and A2A use OAuth 2.1 with PKCE S256, three scopes, tokens bound to https://mcp.mailows.com and revocation checked on each request (30). A key can be issued without send, the person can untick reading or sending at consent, sends need a deny-by-default allowlist, and human mailboxes can't be granted to MCP. Sends go out with no server-side approval step; the manual recommends require_approval: always for OpenAI's API (17 of 20). Message text is returned under untrusted_content, lists carry no subject or body, every message carries DKIM, SPF and DMARC results, attachments are scanned, and the manual sets out an injection-safe pattern. Nothing classifies injection itself (14 of 15). Grants show client, scopes, last use and recipient counts; admin actions are audited for 12 months; a mail journal survives the agent deleting a message. No per-call API log was found (12 of 15). No security.txt on www.mailows.com (404 on 4 November), nor on api.mailows.com or id.namailu.cz per the 21 October check, no disclosure policy, no bug bounty and no certification. The privacy policy promises breach notice without undue delay (2 of 20).

Clawpost 8

Graded with the lines for self-hosted software, since each deployer runs their own Worker. No published package; it deploys from the repository with a Deploy to Cloudflare button, Bun and Wrangler, and states the Cloudflare products it needs (8 of 20). No CI workflow or test suite in the repository (0). Open issues couldn't be read, because GitHub's API refused our requests for its rate limit, so the line scores absent (0, unchecked). No tags, releases or changelog; package.json says 0.1.0 (0). Pre-1.0 (0). Total 8.

Mailows 38

Graded with the hosted lines, on the REST API with the MCP server noted. No status page found. www.mailows.com/status answers 404, status.mailows.com didn't resolve on 21 October and none is linked from the site or its sitemap (0). No readable incident history (5). Limits are described per agent and per account by hour, day and month, monthly units per plan are published and the agents page gives Free 10 sends a day, but hourly numbers for paid plans weren't found (8 of 15, partly met, kept). A 429 carries Retry-After, retry_after_seconds, retry_at and a scope, the manual says to retry network errors, 5xx and 429, a batch is all or nothing, and every send takes an Idempotency-Key honoured for 24 hours (15). The terms give no SLA except one arranged individually on Enterprise (0). The terms of 25 October 2026 and the privacy policy of 30 October 2026 no longer call the service an open beta, and the REST API manual carries no beta or preview label. The MCP manual still describes a pilot for OpenAI clients, outside the graded surface (10).

Clawpost 2

The last commit was on 1 April 2026, 219 days before this check (0). No releases or commits in the 90 days from 8 August (0). Issue and pull request activity couldn't be read through GitHub's API that day (0, unchecked). Not in the official MCP registry and no published package (0). Dependencies such as agents ^0.0.74 and the MCP SDK ^1.12.1 date from early 2026, and there's no CI (2 of 10). Total 2.

Mailows 28

Read for a closed service. No changelog. The MCP registry date of 19 October counted before came from the registry's JSON API, which this method doesn't read, so it is struck. The Stalwart fork has dated commits from 14 to 31 October 2026 but no tag, version or changelog entry, and the server card's version 0.9.2 is undated, so neither is a release. The last dated API change found is Sent-folder storage. The MCP manual says a copy of every sent message now goes to the Sent folder, which the REST API lists with folder=sent, and that nothing was stored before 6 September 2026, 59 days before the check (20). The start of the service on 30 July 2026, the effective date of the first terms, is a page date that records no API change. Only one dated change falls in the 90 days from 6 August (0). Support by email and a contact form, untested, with no public changelog or issue tracker (5 of 15). No official SDKs, and the registry listing that earned this line before is struck (0). No SDK or package to judge; the public Stalwart fork has Dependabot branches (3 of 10).

Clawpost 60

Free self-hosted software with nothing to buy from the author, which the rubric scores 20 + 20 + 20. Running it needs the deployer's own Cloudflare Workers Paid plan at $5 a month, which isn't Clawpost's charge. No payment protocol (0 of 40). Total 60.

Mailows 35

No x402, MPP or L402 in the docs or the OpenAPI file. The OpenAPI file lists five undocumented /acp/checkout_sessions operations with untyped bodies, which no page describes, so no credit (0 of 40). Plan prices are public with VAT and the unit is defined (2 per external recipient, 1 per internal), plus a $12 yearly agent add-on, with no metered per-unit price (10). Free needs no card and doesn't expire, with 200 units (100 external recipients) a month (20). An agent can start a claim ceremony with no browser, but a person has to have signed up in a browser with a bot check, set up 2FA and confirm it, and a person pays at Stripe checkout (5 of 20).

Clawpost 32

The README and SKILL.md say MIT, but no LICENSE file is committed (20 of 30). Self-hosted; the README says mail is stored in the deployer's D1 database with attachments in R2 and sent through Cloudflare Email Service or Resend. No retention or deletion guidance (15 of 30). No deprecation policy (0). No telemetry in the source read; the only outbound calls are to the configured mail provider, Cloudflare's API and the deployer's own webhooks (15 of 20). Total 50.

Mailows 57

A closed service under clear, dated terms naming the operator and New Mexico law (version 2026-10-25.1). The terms promise the source of the two AGPL-3.0 parts; the Stalwart fork is public, but the linked webmail repository isn't (16 of 30). The privacy policy (version 2026-10-30.1) is specific about hosting at Contabo in the EU with administration from the USA, a retention table, backups kept up to 12 months and no training on mail. The terms and the policy now agree on 90 days for message records. They disagree on tracking. The terms say there is no analytics or advertising cookie and no third-party tracking script, and the pricing page says no analytics scripts, while the policy describes OpenAI's advertising pixel and its _oaiq cookie on the public pages, and the home page loads it. That contradiction is charged once, in the misleading-claim term, so this line holds at its earlier 22 for the missing DPA (22 of 30). Terms changes get 30 days' email notice and planned outages are announced, but no API deprecation policy was found and free plans may be limited or discontinued (5 of 20). Processors and locations are named, Contabo (EU and USA), Stripe (EU and USA), OpenAI (USA) and Cloudflare (global) (18 of 20).

Clawpost 53

21 tools, the 11 to 30 band (15 of 25). List and search tools take limit, offset and filters by direction, sender, label and archive state (20). Error shapes aren't documented; the code returns JSON errors (8 of 20). No idempotency key for sends and no readOnlyHint or destructiveHint annotations; drafts give a review step (3 of 20). Archived mail is excluded by default and the CLI has a --json mode, but there's no SDK beyond the CLI (7 of 15). Total 53.

Mailows 75

Graded on the REST API, with the MCP server noted. Message lists return metadata only, the detail returns a limited body with body_truncated, and the MCP server has seven tools assembled from the granted scopes, with a cached tool list (22 of 25). Opaque cursor pagination with limit 1 to 200, unread, since and five folders. No search, and no thread grouping or filter (14 of 20). Errors carry a stable error.code and a plain message, quota errors add when to retry, and MCP errors add a hint (17 of 20). Sends are idempotent on a key for 24 hours on REST and need one on MCP, and the MCP page labels the read-only tools. The OpenAPI file marks the key optional, and MCP annotations weren't read (15 of 20). A send needs only to, but a recipient allowlist must be set first. No official SDKs; the docs show Python requests and Rust reqwest code (7 of 15).