Send16 MCP server

• activate_automationFree

  Activate an automation. New events matching its triggers will start enrolling contacts.

• add_contacts_to_audienceFree

  Add contacts (by ID) to an audience.

• add_convo_noteFree

  Add a private internal note on a conversation. Notes are visible only to workspace members.

• add_domainFree

  Register a new sending domain. Returns the DNS records the user must add to their DNS provider, after which they should call check_domain_health to verify.

• add_suppressionFree

  Add an email to the suppression list. Future sends to this address will be blocked.

• check_domain_healthFree

  Check the DNS health of a specific domain, including DKIM, SPF, DMARC, and MX record verification status. Triggers a fresh DNS lookup.

• create_actionwrite actionFree

  Create an Action that maps an event name to a transactional template. Each matching event sends one email to the contact.

• create_audiencewrite actionFree

  Create a new audience.

• create_campaignwrite actionFree

  Create a new email campaign as a draft: optionally with full HTML content and recipients (exactly ONE of audienceIds / segmentId / contactIds / tagIds / sendToAll) so it's ready to test and send. Nothing is sent until schedule_campaign.

• create_contactwrite actionFree

  Add a single new contact, optionally straight into audiences and/or with tags — e.g. 'add this person from my email into the newsletter list'. Contacts are subscribed by default. For more than a handful of people, use import_contacts instead.

• create_topicwrite actionFree

  Create a new subscription topic. Contacts opt into topics individually via the preference center.

• create_webhookwrite actionFree

  Register an outgoing webhook endpoint. Send16 POSTs event JSON to this URL with an HMAC-SHA256 signature. Outgoing webhooks are a plan feature.

• delete_actionwrite actionFree

  Delete an Action.

• delete_audiencewrite actionFree

  Delete an audience (list). Contacts are not deleted — only the list and its memberships are removed.

• delete_campaignwrite actionFree

  Delete a draft campaign. Sent campaigns cannot be deleted (only archived).

• delete_contactwrite actionFree

  Delete a contact and all associated events. Irreversible.

• delete_topicwrite actionFree

  Delete a subscription topic. All subscribers will be detached.

• delete_webhookwrite actionFree

  Delete an outgoing webhook endpoint.

• design_email_templatewrite actionFree

  Use AI to generate a complete email HTML template based on a description. Returns ready-to-use HTML that can be sent or used in campaigns.

• duplicate_campaignFree

  Duplicate a campaign (template, content, and settings) as a new draft — works on sent campaigns too, so this is the way to re-use a past campaign's design. Optionally rename and retarget in the same call (exactly ONE of audienceIds / segmentId / contactIds / tagIds / sendToAll). NOTE: without retargeting, the copy keeps the ORIGINAL campaign's recipients.

• enroll_in_automationFree

  Manually enroll a contact in an active automation. The automation must be in 'active' status. Use send_event for event-driven enrollment.

• generate_email_from_urlwrite actionFree

  Scrape a URL (e.g. a launch blog post or product page) and generate an email draft from its content. Returns subject, preview text, and HTML body.

• get_actionFree

  Get a single Action with its trigger config and template binding.

• get_automationFree

  Get a single automation by ID, including its trigger, steps, and current status.

• get_automation_statsFree

  Get aggregate analytics for an automation: total enrollments, completed, exited, open/click rates per step.

• get_brandFree

  Get the workspace's brand settings: colors, logo, fonts, and the DESIGN.md spec injected into AI generation prompts.

• get_campaign_statsFree

  Get detailed performance statistics for a specific campaign including open rate, click rate, bounce rate, and delivery metrics.

• get_contact_health_scoreFree

  Get a contact's 0-100 health score based on recent engagement (opens, clicks, replies).

• get_contact_timelineFree

  Get a contact's full activity timeline: emails received, events fired, opens, clicks, automation enrollments, topic changes.

• get_convoFree

  Get a single conversation with its full thread of posts (incoming + outgoing).

• get_deliverability_statusFree

  Get your workspace's deliverability summary — sending reputation, domain authentication status, and recent bounce/complaint health. (Deliverability Hub plan feature.)

• get_messageFree

  Fetch a single message with its full event timeline (created → sent → delivered → opened → clicked → ...).

• get_message_eventsFree

  Get just the delivery event timeline for a message — no body or recipient details.

• get_templateFree

  Get a single starter template by ID, including its EmailContent JSON.

• get_workspaceFree

  Get the current workspace (the one the API key belongs to).

• get_workspace_usageFree

  Get the current month's send count, contact count, and plan limits.

• import_contactsFree

  Bulk import contacts from CSV data (min column: email), optionally straight into audiences and/or with tags. This is the tool for cross-app flows — e.g. pulling people out of Gmail, a CRM, or a spreadsheet and landing them in a Send16 audience in one call. Set updateExisting for upsert semantics (safe to re-run).

• list_actionsFree

  List Actions. Actions fire a transactional template when a custom event arrives — Plunk-style 'event_name → template' pairings, simpler than full automations.

• list_audiencesFree

  List audiences (lists). An audience is a static, manually-managed group of contacts.

• list_automation_enrollmentsFree

  List active and historical enrollments for an automation.

• list_automationsFree

  List all automations in the workspace, including draft/active/paused status and trigger types.

• list_campaignsFree

  List email campaigns, newest first. Use `search` to find a past campaign the user describes vaguely ('the invite one', 'that July newsletter') — it matches name and subject case-insensitively; try distinctive words from their description and broaden if no hits.

• list_contactsFree

  List all contacts with optional filtering by subscription status and tag. Supports pagination.

• list_convosFree

  List inbox conversations. Filter by state, mailbox, label, screener status, or full-text search. Send16's unified inbox combines transactional reply threading with team-managed shared inboxes.

• list_domainsFree

  List all sending domains configured in your Send16 workspace, including their verification status and DNS records.

• list_inbox_countsFree

  Get unread/total counts per category and label for the inbox sidebar (newsletter, transactional, marketing, calendar, social, cold).

• list_messagesFree

  List messages from the unified send log (transactional + campaign). Filter by recipient, sender, status, date range, or source.

• list_segmentsFree

  List dynamic segments. Segments compute their members from a filter expression at send time.

• list_suppressionsFree

  List suppressed email addresses (bounces, complaints, unsubscribes, manual).

• list_templatesFree

  List starter-gallery email templates available to every workspace.

• list_topicsFree

  List subscription topics. Topics are granular categories contacts can subscribe to (e.g. 'product-updates', 'weekly-digest'). Campaigns and automations can be gated to subscribers of a specific topic.

• list_webhooksFree

  List configured outgoing webhooks (your endpoints that Send16 POSTs delivery events to). Outgoing webhooks are a plan feature.

• list_workspacesFree

  List workspaces the authenticated user has access to (owner or member).

• mark_convo_readFree

  Mark a conversation as read for the current viewer.

• pause_automationFree

  Pause an automation. Existing enrollments freeze in place; no new contacts enroll.

• pause_campaignFree

  Pause a sending campaign. Already-sent messages are unaffected; remaining sends halt.

• pre_send_reviewwrite actionFree

  Run an AI pre-send review on an email's HTML before sending. Surfaces tone issues, broken links, missing alt text, spam triggers, and accessibility problems.

• preview_campaign_recipientsFree

  Preview the recipient set for a campaign before sending. Returns count + sample list.

• preview_segmentFree

  Preview the contacts that match a segment without sending.

• regenerate_webhook_secretFree

  Rotate the HMAC signing secret for an outgoing webhook endpoint. Returns the new secret once.

• remove_contact_from_audiencewrite actionFree

  Remove a contact from an audience.

• remove_suppressionwrite actionFree

  Remove an email from the suppression list. Use only when you've confirmed the recipient wants to receive mail again.

• render_email_contentwrite actionFree

  Compile an EmailContent JSON object (the shape used by the Send16 builder + templates) into HTML using the platform's authoritative renderer. Returns the exact HTML the API would send. Useful for previews and post-processing.

• resume_campaignFree

  Resume a paused campaign.

• schedule_campaignFree

  Schedule (or send immediately) an existing draft campaign to an audience/segment/topic.

• screener_decideFree

  Decide a pending screener conversation (first-time sender). 'allow' lets future emails through, 'reject' blocks, 'cold' marks as cold outreach.

• search_contactsFree

  Search contacts by email address or name. Returns matching contacts with their tags and subscription status.

• send_broadcastwrite actionFree

  One-shot broadcast: create a campaign and immediately schedule it to send, in a single call. Pass either an audienceId, segmentId, topicId, or fully-qualified filter. Provide html OR templateSlug.

• send_campaign_testwrite actionFree

  Send a test email for an existing campaign to preview how it will look in recipients' inboxes.

• send_emailwrite actionFree

  Send a transactional email through Send16. Provide `html`, `text`, or both (text-only is fine for OTPs/receipts/alerts). `from_email` must belong to a domain that is verified in the workspace — call `whoami` for the account and `list_domains` to see which senders are allowed; a send from an unverified domain returns a clear error, not a silent failure. For a zero-setup first send, use from_email `onboarding@send16.com` — the sandbox sender delivers with no DNS, but only to your own account email.

• send_eventwrite actionFree

  Fire a custom event for a contact. Automations whose trigger is `{type:'custom_event', eventName:'<name>'}` will enroll the contact and start running. Payload is exposed to condition steps as `event.<key>`.

• send_replywrite actionFree

  Reply to an inbox conversation. The reply is sent from the original recipient address (the alias the convo arrived on) and threaded back to the contact.

• update_actionwrite actionFree

  Update an Action (toggle enabled, change template, change event name).

• update_brandwrite actionFree

  Update workspace brand settings. The designSpec field is a Markdown DESIGN.md document fed into AI generation system prompts — use it to encode voice, do/don't lists, and visual rules.

• update_campaignwrite actionFree

  Update a draft campaign: name, subject, preview text, sender info, HTML content, and/or recipients. Retarget with exactly ONE of audienceIds / segmentId / contactIds / tagIds / sendToAll, then verify with preview_campaign_recipients before sending. Only drafts can be edited.

• update_contactwrite actionFree

  Update a contact's profile fields, custom fields, or subscription state.

• update_convowrite actionFree

  Update conversation status (open/closed/archived/snoozed) or assignee.

• update_topicwrite actionFree

  Update a subscription topic (name, description, default).

• whoamiFree

  Verify the API key and return the authenticated workspace: name, plan, email quota (used/limit), and owner. Call this first to confirm the key works before sending. Pair with list_domains to see which `from` addresses are allowed.

• Code scan3 source files scanned25/25
• Live reliabilityremote reachable in 1974ms20/20
• Tool poisoning79 tool descriptions checked15/15
• Auth qualityopen endpoint exposes 29 write-action tools with no auth3/15
• Maintenancelast push 68 days ago12/15
• Maintainer identityregistry namespace matches repository owner; GitHub account older than a year8/10

Send16: common questions

Is Send16 MCP server safe?

Mostly: it is graded B (83/100). Read the Send16 safety report

How do I install Send16?

It runs remotely at mcp.send16.com. Add it to Claude Code, Claude Desktop or Cursor with the snippets above, or call it through the mcp.market gateway without installing anything.

Does Send16 need an API key?

Yes. The registry entry asks for SEND16_API_KEY.

Is Send16 maintained?

The last commit was 70 days ago (2026-07-19). The latest release is v0.5.8.

Is Send16 up?

100% of our last 28 checks got an answer. We check remote servers about four times a day.

What can I use instead of Send16?

Servers from other publishers that do the same job: MisarMail MCP Server, Agent Email MCP server and Proton Mail (unofficial) MCP server. Compare all Send16 alternatives.