How to Connect ADP with MailerCheck (2026)

Why Connect ADP with MailerCheck

ADP is a leading payroll and human resources management platform that stores employee contact information, organizational data, and workforce records. MailerCheck is an email verification and deliverability tool that validates email addresses and identifies invalid, risky, or disposable addresses before you send campaigns. Connecting ADP with MailerCheck allows HR and internal communications teams to maintain clean, verified employee email lists for company-wide communications, benefits enrollment notices, and payroll notifications.

While this may seem like an unusual pairing, organizations with large or distributed workforces frequently encounter email deliverability issues with employee communications. Verifying employee email addresses ensures that critical HR messages, such as open enrollment deadlines, policy updates, and payroll confirmations, actually reach every employee.

What This Integration Does

An ADP-MailerCheck integration enables you to:

• Export employee email addresses from ADP and run them through MailerCheck's verification service to identify invalid or outdated addresses.
• Automatically verify new employee email addresses when they are added to ADP during the onboarding process.
• Flag employees in ADP whose email addresses fail verification, prompting HR to update the contact information.
• Maintain a continuously clean employee email list for use in internal communications platforms, benefits portals, and notification systems.

Native vs Third-Party Integration

ADP and MailerCheck do not have a native integration. These platforms serve fundamentally different functions, and a direct connector between them does not exist. To connect them, you can use third-party automation tools like Zapier, Make, or n8n.

Zapier supports ADP Workforce Now as a trigger app and MailerCheck as an action app, making it straightforward to set up a verification workflow. Make provides more granular control over data transformation, which is useful if you need to process employee data in bulk before verification. n8n offers a self-hosted option that keeps sensitive employee data within your own infrastructure, which may be important for organizations with strict data handling policies.

Alternatively, you can use MailerCheck's bulk verification feature manually by exporting a CSV of employee emails from ADP and uploading it to MailerCheck's dashboard. This approach works for periodic audits but does not automate ongoing verification.

Step-by-Step Setup

Step 1: Export Employee Email Data from ADP

In ADP Workforce Now, navigate to Reports > Custom Reports or use the People section to generate a list of active employees with their email addresses. If you are setting up an automated workflow, ensure API access is enabled in your ADP account by contacting your ADP administrator or accessing the ADP Marketplace developer portal.

Step 2: Set Up MailerCheck

Log into MailerCheck and navigate to Settings > API to obtain your API key. If you plan to use bulk verification, familiarize yourself with the file upload interface under the Verify section. MailerCheck accepts CSV files and returns results with status codes for each email address.

Step 3: Create the Automation Workflow

In Zapier or Make, create a new workflow. Set the trigger to fire when a new employee is added in ADP or on a scheduled basis (weekly or monthly) to verify all active employee emails. For the action, use MailerCheck's single email verification endpoint to check each address.

Step 4: Handle Verification Results

Configure your workflow to process MailerCheck's verification results. Emails that return as "valid" need no action. For addresses flagged as "invalid," "disposable," or "risky," create a notification step that alerts your HR team to update the employee's contact information in ADP. You can send these alerts via email, Slack, or a shared spreadsheet.

Step 5: Schedule Regular Audits

Set up a recurring schedule for bulk verification. A monthly audit is sufficient for most organizations. Export the full active employee email list from ADP, upload it to MailerCheck, and review the results. Update any flagged addresses in ADP promptly.

Common Use Cases

• Onboarding verification: Automatically verify each new employee's email address as they are entered into ADP, catching typos or invalid addresses before they cause communication failures.
• Benefits enrollment communications: Before sending time-sensitive open enrollment emails, verify all employee email addresses to ensure maximum deliverability.
• Payroll notification deliverability: Ensure that payroll confirmations, tax document notifications, and direct deposit alerts reach every employee by maintaining a verified email list.
• Compliance communications: For regulated industries where employees must acknowledge receipt of policy updates or training requirements, verified email addresses prevent compliance gaps.
• Offboarding cleanup: When employees leave the organization, use the integration to identify and remove deactivated email addresses from active communication lists.

Tips and Best Practices

• Prioritize data security: Employee email addresses are personally identifiable information. Use encrypted connections and ensure your automation platform's data handling practices meet your organization's privacy standards.
• Verify personal and work emails separately: If ADP stores both corporate and personal email addresses, verify them separately and prioritize the corporate email for official communications.
• Do not delete unverified records: If an email fails verification, flag it for review rather than automatically removing it. The address may be valid but temporarily unavailable due to server issues.
• Use MailerCheck's bulk verification for large workforces: For organizations with thousands of employees, bulk verification is more cost-effective and faster than single-email API calls.
• Track verification history: Maintain a log of when each employee's email was last verified and what the result was. This helps identify patterns, such as departments with higher rates of invalid addresses.
• Coordinate with IT: Work with your IT department to ensure that corporate email domains are properly configured with SPF, DKIM, and DMARC records, which affects how MailerCheck evaluates your addresses.