Sendbox
Sendbox is dedicated cold-email infrastructure: your own IPs and mailboxes, real inbox warmup, deliverability monitoring, and a full sending/reply workflow — without sharing infrastructure with anyone else on the platform.
This site documents everything you can do with a Sendbox workspace, whether you’re clicking through the dashboard, calling the REST API directly, or connecting your own LLM to your workspace over MCP.
Where to start
Getting StartedNew to Sendbox? Set up a workspace, connect a mailbox, and send your first campaign.Dashboard GuideEvery page in the dashboard, explained — leads, campaigns, inbox, and more.API ReferenceBuild your own integration against the REST API with a workspace-scoped key.MCP (AI Access)Let Claude or another LLM operate your workspace directly, tool-call by tool-call.
What Sendbox actually does
Dedicated infrastructureYour own sending IPs and mailboxes on every plan, not a shared pool.
Real warmupA social-graph-style warmup network that ramps volume gradually and looks like real mailbox activity, not a bot pattern.
Deliverability monitoringSPF/DKIM/DMARC/MX and blacklist checks run automatically every 6 hours per sending domain, plus on-demand rechecks.
Sequences with A/B variantsMulti-step campaigns with per-step delay, subject/body variants, and a spam-trigger-word checker before you go live.
Unified inboxEvery reply lands in one place, auto-classified by intent, with AI-drafted responses grounded in a knowledge base you control.
A lightweight CRMA pipeline view of every lead who has actually replied, not everyone you've ever emailed.
Real exports and reportsCSV exports and white-label branded reports for agencies.