Setup & Installation
Or with the ClawHub CLI, for registry-managed skill folders outside a full OpenClaw workspace:
Version History
Re-publish: SMTP email verification with MX lookup, RCPT TO check, catch-all detection.
What This Skill Does
Verifies email address deliverability by connecting to the recipient's mail server and running an SMTP check without sending any mail. Resolves MX records, performs a RCPT TO handshake, and detects catch-all domains. Accepts single addresses, multiple addresses, or CSV files.
Checks whether an address is deliverable without sending a message, avoiding bounce penalties, credit consumption, or domain reputation impact.
When to use it
- Checking if a contact email exists before cold outreach
- Cleaning a lead list exported from a CRM
- Validating emails collected through a web form
- Spotchecking an address before adding it to a mailing list
- Filtering invalid addresses from a batch before an email campaign
Example Workflow
Here's how your AI assistant might use this skill in practice.
User asks: verify these emails from leads.csv using the 'Contact Email' column
- 1Reads the CSV and extracts values from the specified email column
- 2Resolves the MX record for each unique domain
- 3Connects to each MX server on port 25 and completes the SMTP handshake
- 4Issues a RCPT TO command to test whether the server accepts each address
- 5Tests a random address per domain to flag catch-all servers
JSON array with deliverability set to yes, no, catch-all, or unknown for each address