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Get Started Free →Manage Mailtrap contacts, lists, segments, custom fields, imports, CRM syncs, and campaign audiences through the UI or API.
.claude/skills/sickn33-mailtrap-managing-contacts/SKILL.md| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-03 | ✗→✓ | ▲ Improved | 79% | 0% |
| case-01 | ✗→✓ | ▲ Improved | 41% | 0% |
| case-02 | ✗→✓ | ▲ Improved | 41% | 0% |
| case-05 | ✗→✓ | ▲ Improved | 107% | 0% |
| case-08 | ✗→✓ | ▲ Improved | 40% | 0% |
Before generating API request bodies: check the Contacts OpenAPI spec for current field names, required parameters, and nested structures.
Contacts are the marketing database: lists, segments, custom fields, and imports for campaign audiences and related workflows. The Contacts API automates create/update and can feed CRM or CDP sync (your code, or tools like Zapier, Make, n8n — see Import contacts).
Suppressions (hard bounces, spam complaints, unsubscribes on the sending side) live in the sending product and block delivery for those addresses on your streams. That is applied separately from marketing filters (segments, list membership, consent flags) that decide who is eligible for campaigns. For sending-side blocks, see Suppressions and mailtrap-sending-emails.
Related skills: mailtrap-sending-emails (live send paths).
All endpoints below need Authorization: Bearer $MAILTRAP_API_TOKEN and an $MAILTRAP_ACCOUNT_ID in the path. Resolve $MAILTRAP_ACCOUNT_ID from GET https://mailtrap.io/api/accounts, and store tokens in environment variables or a secrets manager.
| Action | Method | URL | Reference | | -------------------------------------- | ------- | ----------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------- | | Create / get / update / delete contact | various | https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts | Contacts | | Bulk import (async job) | POST | https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts/imports | Bulk import | | Contact lists | various | https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts/lists | Contact lists | | Custom fields | various | https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts/fields | Contact fields | | Custom events | POST | https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts/{contact_identifier}/events | Contact events | | Export contacts | various | https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts/exports | Export contacts |
GET .../contacts/imports/{import_id}. See Bulk import.curl)bashcurl -X POST "https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts" \ -H "Authorization: Bearer $MAILTRAP_API_TOKEN" \ -H 'Content-Type: application/json' \ -d '{ "contact": { "email": "john.smith@example.com", "fields": {"first_name": "John", "last_name": "Smith", "company": "Example Inc"}, "list_ids": [1, 2, 3] } }'
bashcurl -X POST "https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts/imports" \ -H "Authorization: Bearer $MAILTRAP_API_TOKEN" \ -H 'Content-Type: application/json' \ -d '{ "contacts": [ {"email": "user1@example.com", "fields": {"first_name": "John"}, "list_ids_included": [1, 2]}, {"email": "user2@example.com", "fields": {"first_name": "Jane"}, "list_ids_included": [1]} ] }'
bashcurl -X POST "https://mailtrap.io/api/accounts/$MAILTRAP_ACCOUNT_ID/contacts/{contact_identifier}/events" \ -H "Authorization: Bearer $MAILTRAP_API_TOKEN" \ -H 'Content-Type: application/json' \ -d '{"name": "UserLogin", "params": {"user_id": 101, "is_active": true}}'
POST .../events with an event name and params object for automations.Contacts power marketing campaigns: you maintain clean lists, consent, and attributes here; campaign authoring and scheduling are product features documented in Campaigns.
| Mistake | Fix | | --------------------------------------------------- | ---------------------------------------------------------------------------- | | Hitting rate limits with one-by-one creates | Use /contacts/imports for bulk loads (respect 50k per request) and backoff | | Treating marketing contacts as sending suppressions | Use Suppressions for blocked recipients on send streams |
| Case | Status | Duration (ms) | Turns | Tokens | Tool calls | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Without | With | Δ | Without | With | Δ | Without | With | Δ | Without | With | Δ | ||
case-03 | fail→pass | 7,761 | 4,914 | -37% | 1 | 1 | 0% | 1,569 | 2,807 | +79% | 0 | 0 | — |
case-04 | fail→fail | 9,598 | 6,785 | -29% | 1 | 1 | 0% | 1,935 | 3,016 | +56% | 0 | 0 | — |
case-01 | fail→pass | 10,421 | 4,812 | -54% | 1 | 1 | 0% | 2,007 | 2,828 | +41% | 0 | 0 | — |
case-02 | fail→pass | 11,073 | 5,001 | -55% | 1 | 1 | 0% | 2,007 | 2,822 | +41% | 0 | 0 | — |
case-05 | fail→pass | 7,360 | 5,519 | -25% | 1 | 1 | 0% | 1,498 | 3,105 | +107% | 0 | 0 | — |
case-06 | pass→pass | 9,301 | 6,436 | -31% | 1 | 1 | 0% | 1,569 | 2,780 | +77% | 0 | 0 | — |
case-07 | pass→pass | 7,255 | 2,264 | -69% | 1 | 1 | 0% | 1,399 | 2,203 | +57% | 0 | 0 | — |
case-08 | fail→pass | 11,577 | 5,488 | -53% | 1 | 1 | 0% | 2,056 | 2,882 | +40% | 0 | 0 | — |
case-09 | fail→pass | 6,649 | 3,199 | -52% | 1 | 1 | 0% | 1,118 | 2,353 | +110% | 0 | 0 | — |
case-10 | pass→pass | 7,561 | 3,328 | -56% | 1 | 1 | 0% | 1,382 | 2,421 | +75% | 0 | 0 | — |
case-11 | fail→pass | 8,885 | 3,779 | -57% | 1 | 1 | 0% | 1,703 | 2,769 | +63% | 0 | 0 | — |
case-12 | fail→pass | 9,088 | 4,706 | -48% | 1 | 1 | 0% | 1,724 | 2,754 | +60% | 0 | 0 | — |
case-13 | fail→pass | 6,417 | 2,936 | -54% | 1 | 1 | 0% | 1,147 | 2,343 | +104% | 0 | 0 | — |
case-14 | fail→pass | 14,213 | 2,950 | -79% | 1 | 1 | 0% | 2,846 | 2,416 | -15% | 0 | 0 | — |
case-15 | fail→pass | 10,089 | 2,554 | -75% | 1 | 1 | 0% | 1,618 | 2,219 | +37% | 0 | 0 | — |
case-16 | pass→pass | 4,435 | 2,075 | -53% | 1 | 1 | 0% | 758 | 2,109 | +178% | 0 | 0 | — |
case-17 | pass→pass | 11,229 | 5,303 | -53% | 1 | 1 | 0% | 1,813 | 2,756 | +52% | 0 | 0 | — |
case-18 | fail→pass | 6,949 | 3,549 | -49% | 1 | 1 | 0% | 1,293 | 2,546 | +97% | 0 | 0 | — |
case-19 | pass→pass | 10,993 | 2,906 | -74% | 1 | 1 | 0% | 1,843 | 2,318 | +26% | 0 | 0 | — |
case-20 | pass→pass | 10,357 | 6,161 | -41% | 1 | 1 | 0% | 1,507 | 2,820 | +87% | 0 | 0 | — |
case-21 | fail→fail | 6,503 | 3,852 | -41% | 1 | 1 | 0% | 1,248 | 2,548 | +104% | 0 | 0 | — |
case-22 | fail→pass | 5,799 | 2,824 | -51% | 1 | 1 | 0% | 1,092 | 2,325 | +113% | 0 | 0 | — |
DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 22 cases were attempted. The headline lift of +59 percentage points is the difference between those two pass rates over the 22 comparable cases.
Without the skill loaded, the model failed this case. With it loaded, the same prompt on the same model passed. This is one improved case from the latest verified run; every case, including any that regressed, is in the table above.
Other measured skills in the registry, with their headline benchmark lift.