{"generated_at":"2026-10-14T20:07:22+00:00","item":{"added_at":"2026-06-23","analysis_method":"independent_manual_review_2026-10-10","assessment_status":"provisional","auth_posture":"auth_required","category":"Web Connector","confidence":"medium","description":"Send and manage transactional email with MailerSend. Compose or schedule messages, track delivery and verify email addresses. Configure domains and webhooks, and browse or remove existing templates.","did":"172cf913-f059-495a-a9fd-3f470bf36b10","documentation_url":"https://developers.mailersend.com/mcp","editorial_description":{"extended_description":"Messages can include HTML, plain text, attachments, templates and CC/BCC recipients. Review opens, clicks, bounces or complaints and cancel scheduled sends. Domain verification, bulk address checks and webhook changes support ongoing mail operations.","schema_version":1,"summary":"Send and manage transactional email with MailerSend.\nCompose or schedule messages, track delivery and verify email addresses.\nConfigure domains and webhooks, and browse or remove existing templates."},"homepage_url":"","icon":"","id":"172cf913-f059-495a-a9fd-3f470bf36b10","installs":0,"last_scanned":"","license":"","long_description":"Messages can include HTML, plain text, attachments, templates and CC/BCC recipients. Review opens, clicks, bounces or complaints and cancel scheduled sends. Domain verification, bulk address checks and webhook changes support ongoing mail operations.","manual_assessment":"high","manual_review":{"all_findings":[{"evidence":"The listing says send_email composes and sends HTML or text email with CC, BCC, attachments, templates and optional scheduling.","reasoning":"It transmits external messages as the authenticated MailerSend sender.","risk_type":"messaging_as_user","severity":"high","title":"Sends transactional email with recipients and attachments","triggering_tools_or_skills":["send_email"]},{"evidence":"The complete inventory explicitly deletes several persistent account resources.","reasoning":"These actions can remove sending configuration, content and pending communications.","risk_type":"data_deletion","severity":"high","title":"Deletes domains, scheduled messages, templates and webhooks","triggering_tools_or_skills":["delete_domain","delete_scheduled_message","delete_template","delete_webhook"]},{"evidence":"The connector adds sending domains, changes their settings and triggers verification.","reasoning":"Sending-domain control is a powerful identity and email-security capability.","risk_type":"credential_admin","severity":"high","title":"Adds and verifies sending domains","triggering_tools_or_skills":["add_domain","update_domain_settings","verify_domain"]},{"evidence":"Webhook creation and update configure external event delivery destinations.","reasoning":"The target URL may be caller-selected, subject to undocumented validation.","risk_type":"arbitrary_network_access","severity":"low","title":"Creates webhooks with caller-controlled endpoints","triggering_tools_or_skills":["create_webhook","update_webhook"]},{"evidence":"The connector reads message history, recipient activity, bounces and complaints.","reasoning":"Recipient-controlled and message content can contain adversarial instructions.","risk_type":"prompt_injection_exposure","severity":"low","title":"Messages and webhook activity contain external content","triggering_tools_or_skills":["get_message","list_messages","get_activity","list_activities"]}],"assessment_status":"provisional","auth_and_scopes":"OAuth scopes access to the connected MailerSend account without exposing its API key; exact sender-domain, recipient and webhook permissions are not documented.","blocked_missing_evidence":null,"confidence":"medium","displayed_risk":"high","evidence_completeness":"partial","manual_overall_risk":"high","official_sources":[{"accessed_at":"2026-10-10T20:24:37Z","url_or_path":"plutosecurity/plutonium@b749c8dc43536c794409be9805edd48063f045e2:app/data/conn/claudesec/172cf913-f059-495a-a9fd-3f470bf36b10.json","what_it_proves":"Candidate PR #125 record identity (name \"MailerSend\", publisher, type web_connector) and 38 stored tool names; no tool descriptions stored"},{"accessed_at":"2026-09-22T10:46:07Z","url_or_path":"https://api.anthropic.com/api/directory/servers?verified_tier=anthropic,partner,community (snapshot claude-directory-all-tiers-2026-09-22.json)","what_it_proves":"Official Claude Directory listing https://claude.ai/directory/172cf913-f059-495a-a9fd-3f470bf36b10: complete tool_names inventory (38 tools), remote streamable-http endpoint https://mcp.mailersend.com/mcp, auth_posture auth_required, directory tier community"}],"primary_reason":"The connector sends external email, deletes account resources and administers sending domains.","provisional_risk":null,"publication_recommendation":"accept","requires_runtime_verification":true,"review_key":"claude:172cf913-f059-495a-a9fd-3f470bf36b10","reviewed_at":"2026-10-10","reviewer_notes":"Reviewed all 38 names. Runtime verification should establish recipient limits, confirmation, plan-credit effects and webhook target restrictions.","risk_domains":{"arbitrary_network_access":"true","authz_ambiguity":"true","browser_control":"false","credential_or_admin_actions":"true","deletes_data":"true","deployment_or_infrastructure":"false","dynamic_hidden_actions":"false","filesystem_or_repo_access":"false","forwards_data_to_third_party":"true","modifies_data":"true","persistent_credentials":"true","prompt_injection_exposure":"true","provenance_uncertainty":"true","reads_private_data":"true","runs_code_or_queries":"false","sends_messages_as_user":"true","spends_or_moves_money":"unknown"},"tools_or_skills_reviewed":38,"tools_or_skills_total":38},"name":"MailerSend","needs_runtime_verification":true,"plutonium_url":"https://plutonium.pluto.security/detail.html?planet=claudesec&did=172cf913-f059-495a-a9fd-3f470bf36b10&utm_source=plutonium_analysis_skill&utm_medium=claude_skill&utm_campaign=connector_risk_assessment","privacy_policy_url":"https://www.mailersend.com/legal/privacy-policy","provisional_risk":null,"publication_recommendation":"accept","publisher":"MailerSend","publisher_url":"https://www.mailersend.com/","remote_url":"https://mcp.mailersend.com/mcp","repository_url":"","risk":"high","risk_severity":"high","security_risks":[{"description":"This connector can publish or send messages and content using the connected identity. Review findings: It transmits external messages as the authenticated MailerSend sender.","evidence":"Sends transactional email with recipients and attachments: The listing says send_email composes and sends HTML or text email with CC, BCC, attachments, templates and optional scheduling.","manual_risk_type":"messaging_as_user","remediation":{"block_tool_categories":["sends_externally"],"steps":["Require review before messages, posts, or publications are sent.","Restrict delivery to test or internal recipients where possible."]},"risk_type":"sends_messages_as_you","severity":"high","title":"Sends transactional email with recipients and attachments","triggering_tools":["send_email"]},{"description":"This connector can permanently remove data or resources. Review findings: These actions can remove sending configuration, content and pending communications.","evidence":"Deletes domains, scheduled messages, templates and webhooks: The complete inventory explicitly deletes several persistent account resources.","manual_risk_type":"data_deletion","remediation":{"block_tool_categories":["destructive"],"steps":["Disable destructive tools unless deletion is an explicit workflow requirement.","Require human confirmation and verified backups before deletion."]},"risk_type":"deletes_data","severity":"high","title":"Deletes domains, scheduled messages, templates and webhooks","triggering_tools":["delete_domain","delete_scheduled_message","delete_template","delete_webhook"]},{"description":"This connector can create, update, configure, or otherwise change connected resources. Review findings: Sending-domain control is a powerful identity and email-security capability.","evidence":"Adds and verifies sending domains: The connector adds sending domains, changes their settings and triggers verification.","manual_risk_type":"credential_admin","remediation":{"block_tool_categories":["state_change"],"steps":["Use a test account or sandbox before allowing changes to production data.","Grant only the write permissions required for the intended workflow.","Require human confirmation for consequential state changes."]},"risk_type":"modifies_data","severity":"high","title":"Adds and verifies sending domains","triggering_tools":["add_domain","update_domain_settings","verify_domain"]},{"description":"This connector can send caller-provided data to an external service or publisher. Review findings: The target URL may be caller-selected, subject to undocumented validation.","evidence":"Creates webhooks with caller-controlled endpoints: Webhook creation and update configure external event delivery destinations.","manual_risk_type":"arbitrary_network_access","remediation":{"block_tool_categories":["sends_externally"],"steps":["Do not include secrets, regulated data, or customer information unless the destination is approved.","Review the recipient's retention and deletion policy before enabling the connector."]},"risk_type":"forwards_data_to_third_party","severity":"low","title":"Creates webhooks with caller-controlled endpoints","triggering_tools":["create_webhook","update_webhook"]}],"signature_status":"unknown","source_code_reviewed":false,"support_url":"support@mailersend.com","tags":["accesses_messaging","deletes_data","forwards_data_to_third_party","modifies_data","network_access","oauth_required","sends_messages_as_you","web_connector"],"tools":[{"description":"","name":"add_domain","risk":{"category":"state_change","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can create, update, configure, or otherwise change connected resources. Review findings: Sending-domain control is a powerful identity and email-security capability."}},{"description":"","name":"create_verification_list"},{"description":"","name":"create_webhook"},{"description":"","name":"delete_domain","risk":{"category":"destructive","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can permanently remove data or resources. Review findings: These actions can remove sending configuration, content and pending communications."}},{"description":"","name":"delete_scheduled_message","risk":{"category":"destructive","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can permanently remove data or resources. Review findings: These actions can remove sending configuration, content and pending communications."}},{"description":"","name":"delete_template","risk":{"category":"destructive","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can permanently remove data or resources. Review findings: These actions can remove sending configuration, content and pending communications."}},{"description":"","name":"delete_webhook","risk":{"category":"destructive","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can permanently remove data or resources. Review findings: These actions can remove sending configuration, content and pending communications."}},{"description":"","name":"fetch"},{"description":"","name":"get_activity"},{"description":"","name":"get_analytics_by_country"},{"description":"","name":"get_analytics_by_date"},{"description":"","name":"get_analytics_by_user_agent_name"},{"description":"","name":"get_analytics_by_user_agent_type"},{"description":"","name":"get_async_verification_status"},{"description":"","name":"get_auth_status"},{"description":"","name":"get_dns_records"},{"description":"","name":"get_domain"},{"description":"","name":"get_message"},{"description":"","name":"get_scheduled_message"},{"description":"","name":"get_template"},{"description":"","name":"get_verification_list"},{"description":"","name":"get_verification_results"},{"description":"","name":"get_webhook"},{"description":"","name":"list_activities"},{"description":"","name":"list_domains"},{"description":"","name":"list_messages"},{"description":"","name":"list_scheduled_messages"},{"description":"","name":"list_templates"},{"description":"","name":"list_verification_lists"},{"description":"","name":"list_webhooks"},{"description":"","name":"search"},{"description":"","name":"send_email","risk":{"category":"sends_externally","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can publish or send messages and content using the connected identity. Review findings: It transmits external messages as the authenticated MailerSend sender."}},{"description":"","name":"update_domain_settings","risk":{"category":"state_change","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can create, update, configure, or otherwise change connected resources. Review findings: Sending-domain control is a powerful identity and email-security capability."}},{"description":"","name":"update_webhook"},{"description":"","name":"verify_domain","risk":{"category":"state_change","level":"high","recommendation":"Follow the connector-level remediation and require approval for consequential actions.","why":"This connector can create, update, configure, or otherwise change connected resources. Review findings: Sending-domain control is a powerful identity and email-security capability."}},{"description":"","name":"verify_email"},{"description":"","name":"verify_email_async"},{"description":"","name":"verify_list"}],"tools_count":38,"transport":"streamable-http","type":"web_connector","url":"https://claude.ai/directory/172cf913-f059-495a-a9fd-3f470bf36b10","uuid":"a64b8d21-8cd2-52b9-8705-2ef5400b11e8","verification_tier":"community","version":""},"query_key":"mailersend mailersend","schema_version":1,"status":"match"}