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sending-emails

Use when integrating, configuring, or troubleshooting Mailtrap live email sending (Email API or SMTP). Use when wiring outbound mail from an application or choosing how to send.

Quality

84%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

82%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A strong, highly actionable reference: executable curl examples, precise endpoint/credential tables, a clear integration preference order, and a useful common-mistakes table. The only notable deductions are mild repetition of the batch/bulk distinction, a missing post-send verification step, and reference material kept inline rather than split into bundle files.

DimensionReasoningScore

Conciseness

Dense tables and examples with no explanation of concepts Claude already knows, but the batch-vs-bulk distinction is repeated in three places (Overview, the "Choosing how to send" table, and "Common mistakes") and endpoint info appears in both the decision table and the Quick reference. This matches anchor 4 (minor trimming possible) rather than 5 (every token earns its place).

4 / 5

Actionability

Copy-paste-ready curl examples with real endpoints, auth headers, and JSON bodies cover the common cases (transactional, bulk, batch, template); SMTP host/port/credential tables and a concrete rate limit with "Use backoff on 429" round it out. This is a direct match for anchor 5.

5 / 5

Workflow Clarity

The numbered preference order (plugin → SDK → HTTP API → SMTP) plus the decision table give a clear, well-sequenced workflow, with pre-send checkpoints supplied by reference (domain verification, testing-with-sandbox) and 429 backoff guidance. It is below anchor 5 because post-send verification (e.g., checking the API response) is not addressed, and above anchor 3 because most checkpoints are present.

4 / 5

Progressive Disclosure

No bundle files exist; the body is well-sectioned and appropriately offloads depth to clearly signaled external targets (full request schemas → official Mailtrap docs, token handling → authorizing-api-requests, SDK usage → repo READMEs, related skills by name). It is not 5 because reference material such as the full example set, SDK list, and suppressions section are inlined in a ~150-line file with no reference-file split, fitting anchor 4 (good structure, minor organization gaps).

4 / 5

Total

17

/

20

Passed

Description

78%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A tight, trigger-focused description with excellent explicit "Use when" guidance and a clear product niche. Its main weakness is that the capability side (what the skill covers) is only implied by the domain phrase rather than stated outright, and a few natural synonyms (transactional, bulk, marketing email) are absent.

Suggestions

Add a leading third-person capability statement (e.g., "Guides live email sending through Mailtrap via the Email API (REST) or SMTP.") so the "what" is explicit rather than embedded in the when-clauses.

Include common user synonyms such as "transactional email", "bulk email", or "marketing email" to broaden natural trigger coverage.

Consider naming the key sub-decisions (stream choice, batch vs. single send) in the description so searches about those topics surface this skill.

DimensionReasoningScore

Specificity

"integrating, configuring, or troubleshooting" plus "wiring outbound mail" and "choosing how to send" list several concrete actions tied to the named domain ("Mailtrap live email sending (Email API or SMTP)"). It is not 5 because actions appear only as trigger conditions with no capability statement, and not 3 because coverage clearly exceeds 1-2 actions.

4 / 5

Completeness

The "when" is explicit and strong ("Use when integrating... Use when wiring outbound mail..."), and the "what" is present but only embedded in the when-clauses ("Mailtrap live email sending (Email API or SMTP)") rather than stated as a leading capability. This sits noticeably above anchor 3 but below anchor 5, which requires an explicit standalone what-statement.

4 / 5

Trigger Term Quality

Natural phrases users would say are present: "integrating", "troubleshooting", "sending" email, "SMTP", "Email API", "outbound mail". A few common variations are missing (e.g., "transactional email", "bulk"/"marketing email"), matching anchor 4 rather than 5.

4 / 5

Distinctiveness Conflict Risk

"Mailtrap" plus "live email sending" carves a clear niche and explicitly distinguishes from sandbox/testing usage, giving minimal conflict risk with other skills — a direct match for anchor 5.

5 / 5

Total

17

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

mailtrap/mailtrap-skills

Path

skills/sending-emails/SKILL.md

Reviewed

Table of Contents

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