# MailerCheck MCP > MailerCheck validates email addresses in real-time or processes entire lists of contacts for deliverability testing. It helps marketing teams ensure high sender reputation by instantly checking if an address is valid, risky, or outright fake. Whether you're running a campaign or cleaning up old CRM data, this MCP guarantees your outreach efforts hit real people, minimizing costly bounce rates and maximizing engagement. ## Overview - **Category:** security-compliance - **Price:** Free - **Tags:** email-verification, deliverability, sender-reputation, data-hygiene, validation-api ## Description You can connect this MCP to any AI agent and make sure every email address in your contact lists actually works before sending anything out. It handles two types of checks: instant verification for single addresses, or processing massive batches of emails all at once. If you’re building an automated outreach system, you use it to upload a list and then track the progress until you get detailed reports showing exactly which addresses failed and why. You can even check your account credits anytime just by asking. This functionality integrates smoothly into any workflow; connecting through Vinkius gives you access to this powerful validation tool alongside thousands of others, letting your agent handle all your data hygiene needs from one place. ## Tools ### get_account_info Retrieves current account details and your remaining verification credit balance. ### get_batch_results Fetches the comprehensive outcomes for a specific, completed batch job ID. ### list_verification_batches Lists all recent email verification jobs you've run and their corresponding IDs. ### create_verification_batch Accepts a list of emails to process them asynchronously for large-scale validation. ### verify_single_email Performs an instant, real-time check on just one email address string. ## Prompt Examples **Prompt:** ``` Verify the email address 'user@example.com' in MailerCheck. ``` **Response:** ``` I've checked the address. 'user@example.com' is marked as 🟢 VALID. You can safely send to this recipient. ``` **Prompt:** ``` List all my recent verification batches. ``` **Response:** ``` I've retrieved your batches. You have 3 recent jobs: 'Main Website Leads (ID: 123)', 'Old CRM Export', and 'Newsletter Cleanup'. Would you like to see the results for any of them? ``` **Prompt:** ``` Show valid emails for batch ID '123'. ``` **Response:** ``` I've queried the results for batch 123. There are 45 valid email addresses, including 'admin@corp.com' and 'sales@firm.io'. I've filtered out risky and invalid results. ``` ## Capabilities ### Check a single email address Instantly determines if an individual email is valid or problematic. ### Validate large lists of emails Uploads multiple email addresses to run comprehensive, background checks on the entire group. ### Track batch progress and results Retrieves detailed status reports for any verification job you've submitted, including failure reasons. ### Monitor account usage Provides current details on your account standing and remaining credit balance. ## Use Cases ### A new CRM export arrives with questionable data. The SDR downloads 5,000 leads from a third party. Instead of just importing them, they ask their agent to use `create_verification_batch`. The agent handles the upload and waits until the batch is done, providing a clean list ready for immediate segmentation. ### Need to check a specific lead's address before calling. A marketing specialist gets an email from a hot prospect. They don't want to waste time reaching out only to get bounced. They ask the agent to run `verify_single_email` on the contact immediately, confirming it's safe to proceed. ### Reviewing last month’s campaign performance. The marketing team needs to audit which leads were invalid in a past mailing. They instruct their agent to use `list_verification_batches` first, then select the correct batch ID and run `get_batch_results` to see exactly who was marked as risky or invalid. ### Building automated data ingestion. A growth engineer needs a continuous data feed. They ask their agent to first check account health with `get_account_info`, and then set up a recurring job using `create_verification_batch` to keep the master list clean. ## Benefits - Maintain sender reputation and high deliverability. By using the `verify_single_email` tool, you check every address before it leaves your system, protecting your domain's standing. - Eliminate painful list cleanup cycles. Instead of manual scrubbing, use `create_verification_batch` to upload thousands of contacts and process them in the background. - Get actionable data on failures. When a batch is done, the `get_batch_results` tool doesn't just say 'fail'; it gives reason codes, telling you *why* an email failed. - Never worry about credits again. The `get_account_info` function lets your agent monitor your current usage and credit balance at a glance. - Keep track of everything easily. Use the `list_verification_batches` tool to maintain a clear record and ID for every verification job you run. ## How It Works The bottom line is that you tell your agent what emails need fixing, and it handles the connection to run the checks. 1. First, subscribe to this MCP and enter your required MailerCheck API token. 2. Second, instruct your AI client to either verify one specific email or upload a list for batch checking. 3. Finally, the agent returns a detailed report containing the validation status (valid, risky, invalid) for every address processed. ## Frequently Asked Questions **How do I check one email address with MailerCheck?** You use the `verify_single_email` tool. Just ask your agent to verify a specific email, and it gives you an immediate status update on validity. **Can I validate 10,000 emails using MailerCheck?** Yes, use the `create_verification_batch` tool. This is designed for bulk processing; upload your list and let the system handle the validation asynchronously. **Where do I find out why an email failed with MailerCheck?** After a batch job completes, use `get_batch_results`. This tool provides detailed reason codes for every failure, so you know exactly what needs fixing in your source data. **How do I check my remaining credits with MailerCheck?** Run the `get_account_info` function. It immediately gives you an overview of your account details and how many verification credits you have left to spend.