TrueList
TrueList validates email addresses, manages batch validation jobs, and retrieves validation history.
Verdict
Common use cases
- Scrub a lead list before launching a cold campaign
- Check conference attendee emails for typos
- Validate form submissions in real time
- Audit subscriber health before a product launch
- Estimate validation cost for a new data source
Integration
- Vendor
- TrueList
- Category
- other
- Auth
- API_KEY
- Tools
- 8
- Composio slug
true_list
Tools
- Create Batch
Create an asynchronous TrueList batch email-validation job from tabular rows. A successful call consumes validation credits, so use ESTIMATE_BATCH first when cost or row counts are uncertain.
- Delete Batchdestructive
Permanently delete one completed TrueList batch and its validation results. This destructive operation cannot be undone, and TrueList rejects deletion when the batch is missing or has not completed.
- Estimate Batch
Estimate email count, duplicates, and processing time for tabular batch data without creating a batch or consuming batch-validation credits.
- Get Account
Return the connected TrueList user identity, account name, and payment plan without exposing API tokens or other account users.
- Get Batch
Get one TrueList batch-validation job by UUID, including progress counts and completed result download URLs. The provider may return nonterminal states including pending, pending_processing, processing, and finalizing.
- List Batches
List all batch-validation jobs in the connected TrueList account, including their current processing state, progress counts, and available result download URLs. TrueList returns the complete list without documented pagination.
- List Validation History
Return one page of previously validated email results, optionally filtered by batch, address, state, or sub-state.
- Validate Email
Validate one email address synchronously, consume validation capacity, and add the result to TrueList validation history.
Setup
Setup guide
- 11. Open your Switchy workspace settings and navigate to the Integrations tab. 2. Search for TrueList and click Connect. 3. You'll be prompted to paste a TrueList API key; log in to your TrueList dashboard, navigate to API Settings, and generate a new key if you don't have one. 4. Copy the key and paste it into Switchy, then click Authorize. 5. Switchy will confirm the connection by fetching your account details. 6. Inside any Project, type '@TrueList validate the email john@example.com' to test—the MCP will return a validation result showing deliverability and risk flags. 7. For batch jobs, use '@TrueList estimate batch' with a table of emails to see credit cost before committing, then '@TrueList create batch' to launch the job.
What teammates see: by default, memories from TrueList are scoped to the Project (PROJECT visibility) - you can mark any memory PRIVATE or share it ORG-wide.
Works well with
Top models
Compatibility data appears once enough Projects have used this MCP together with a given model.
How Switchy teams use it
Starter prompts
Validate Single Address
@TrueList validate the email address sarah.jones@acmecorp.io and tell me if it's safe to send to.
Estimate Batch Cost
@TrueList estimate batch for these emails: alice@startup.com, bob@startup.com, alice@startup.com, carol@vendor.net. Show me the count and duplicate summary.
Launch Bulk Validation
@TrueList create batch with these rows: name,email / Alice,alice@startup.com / Bob,bob@vendor.net / Carol,carol@agency.org. Let me know the batch UUID.
Check Batch Status
@TrueList get batch f47ac10b-58cc-4372-a567-0e02b2c3d479 and show me the current progress and any download links.
Review Validation History
@TrueList list validation history filtered by state 'invalid' so I can see which emails bounced and why.
Example outputs
Illustrative - representative of the model's voice and quality, not literal recordings.
@TrueList validate the email address support@example-startup.io and tell me if it's deliverable
TrueList validated support@example-startup.io and returned a "valid" state with sub-state "valid_mailbox". The MX records resolve correctly, the mailbox exists, and the address passed syntax checks. This result consumed one validation credit from your account and was added to your validation history. The address appears safe to use for outreach or onboarding workflows.
This example shows single-email validation — the fastest way to check an address before sending. Each call consumes one credit, so batch validation is more cost-effective for lists over ~50 addresses. Requires API_KEY auth with validation permissions.
@TrueList estimate how many credits I'd need to validate this CSV of 2,400 conference attendee emails before I commit to running the batch
TrueList's ESTIMATE_BATCH tool analyzed your CSV and found 2,400 total rows with 2,187 unique email addresses after deduplication. The estimate indicates this batch would consume approximately 2,187 validation credits and take 8–12 minutes to process. No credits were charged for this estimate, so you can decide whether to proceed with CREATE_BATCH or refine your list first.
This example highlights the cost-preview workflow — essential when working with large or unknown datasets. The estimate call is free and prevents surprise credit consumption. Always run ESTIMATE_BATCH before CREATE_BATCH when row counts or duplicate rates are uncertain.
@TrueList pull my last 100 validation results and summarize how many bounced due to invalid mailboxes versus syntax errors
TrueList returned 100 recent validation results from your history. The AI parsed the state and sub-state fields and found: 12 addresses marked "invalid" with sub-state "invalid_mailbox" (mailbox does not exist), 5 marked "invalid" with sub-state "invalid_syntax" (malformed addresses), and 83 marked "valid". This breakdown suggests most failures are due to nonexistent mailboxes rather than typos, which may indicate outdated contact lists.
This example pairs TrueList's LIST_VALIDATION_HISTORY tool with AI reasoning to surface patterns in validation outcomes. Useful for diagnosing data-quality issues across campaigns. The history endpoint supports filtering by batch UUID, address, or state if you need narrower queries.
Use-case deep-dives
When batch validation beats real-time checks for conference signups
A 6-person events team runs quarterly conferences and collects 2,000–5,000 registrations per event. They export the signup CSV from Eventbrite every Monday to scrub bounces before the email drip starts. TrueList's ESTIMATE_BATCH tool lets them preview duplicate counts and credit cost before committing, then CREATE_BATCH runs the full validation overnight. The team downloads results Tuesday morning and filters out disposable domains and syntax errors in their CRM. This MCP is the right call when you validate in batches larger than 500 rows and can wait 12–24 hours for results. If you need instant feedback during a live signup form, the single VALIDATE_EMAIL tool works but burns credits faster and doesn't dedupe. For event teams running predictable weekly or monthly scrubs, the batch workflow pays for itself in credit savings and eliminates manual CSV round-trips.
Why TrueList wins for outbound prospecting lists under 10k contacts
A 3-person sales team at a Series A SaaS company buys lead lists from ZoomInfo and Apollo, then validates emails before loading them into Outreach. They paste 1,500 rows into a shared Switchy thread, call ESTIMATE_BATCH to confirm credit cost, then CREATE_BATCH and poll GET_BATCH until the job completes. The validation history (LIST_VALIDATION_HISTORY) becomes a shared knowledge base: the team searches by domain to see which vendors consistently deliver clean contacts. This MCP is ideal when your list size sits between 500 and 10,000 rows and you validate weekly or monthly. Above 10k rows, TrueList's async batch can take 48+ hours and the API starts returning timeouts on GET_BATCH polls. Below 500 rows, the single-email VALIDATE_EMAIL tool is faster but costs more per contact. For mid-market sales teams running regular prospecting sprints, the batch workflow and validation history make TrueList the default.
When real-time validation makes sense for support intake forms
A 12-person support team at a B2C fintech handles 300–500 inbound tickets daily through Zendesk. Customers frequently mistype their email when submitting a ticket, and the team wastes 20 minutes per day chasing bounced replies. They add TrueList's VALIDATE_EMAIL tool to their Switchy workflow: when a ticket arrives with a suspicious-looking email, the agent calls the tool inline and gets an instant verdict (valid, invalid, disposable, role-based). If the result is invalid or disposable, they reply in-app instead of by email. This MCP is the right call when you validate one-off emails in real time and need results in under 5 seconds. The single-email tool consumes more credits than batch validation, so it's expensive if you're scrubbing bulk lists. For support teams where speed trumps cost and validation volume stays under 100 emails per day, the real-time workflow prevents reply bounces without adding a batch export step.
Frequently asked
What does the TrueList MCP do in Switchy?
It validates email addresses and runs bulk verification jobs inside your Switchy workflows. You can check single emails synchronously, launch batch jobs from CSV data, estimate costs before committing credits, and pull validation history. Every validation call consumes credits from your TrueList account, so the MCP exposes an estimate tool to preview counts and duplicates before you run the real batch.
Do I need a paid TrueList account to use this MCP?
Yes. You need an active TrueList account with validation credits and an API key. The MCP calls Get Account to confirm your identity and plan tier, but it won't create an account or add credits for you. If you hit zero credits mid-batch, TrueList will reject the job and Switchy will surface that error in the workflow log.
Can the MCP clean my email list without using credits?
No. Only the Estimate Batch tool runs without consuming credits; it counts rows and flags duplicates but doesn't validate deliverability. Every other validation operation—single-email checks and actual batch jobs—debits your TrueList balance immediately. Use the estimate step first if you're unsure whether the list size fits your budget.
How is this different from calling TrueList's API directly?
The MCP wraps TrueList's REST endpoints so your Switchy agents can validate emails mid-conversation without you writing HTTP boilerplate. You still pay TrueList's per-validation pricing and follow their rate limits, but the integration handles auth headers, batch polling, and result parsing automatically. If you already have custom scripts that work, you don't need to migrate.
Who on my team should connect the TrueList MCP?
Whoever owns your TrueList account and API key. That person adds the key to Switchy once; then any workspace member can invoke validation tools in their workflows. Batch jobs and history queries run under the connected account's credit pool, so coordinate with your finance or ops lead if multiple people will trigger large validations.