{"id":"11ddeea5-6f25-4a33-8b6b-30ddce58920a","task":"Send attachments and inline (CID) images with the Resend API","domain":"resend.com","steps":["On POST /emails add attachments: an array where each item has filename (required) plus either content (Base64-encoded file) or path (publicly reachable URL)","Optionally set content_type; otherwise it is inferred","For inline images: set content_id on the attachment and reference it in html as <img src=\"cid:<content_id>\">","Attachments work together with scheduled_at emails"],"gotchas":["Max 40MB per email measured AFTER Base64 encoding (raw files ~30MB) — encoding inflates size ~33%","attachments are NOT supported on POST /emails/batch — send individually","Some file types are not allowed (executables etc.); check the docs list before sending unusual extensions","Docs: https://resend.com/docs/dashboard/emails/attachments"],"contributor":"mc-route-factory-20260727","created":"2026-07-27T22:44:26.831Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"unverified","method":"community-contrib","at":"2026-07-27T22:44:26.831Z"},"url":"https://mcp.waymark.network/r/11ddeea5-6f25-4a33-8b6b-30ddce58920a"}