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POST
/
contacts
/
validate
curl -X POST https://api.unosend.co/contacts/validate \
  -H "Authorization: Bearer un_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "john@company.com",
    "check_catch_all": true
  }'

{
  "success": true,
  "data": {
    "email": "john@company.com",
    "valid": true,
    "score": 90,
    "reason": null,
    "checks": {
      "syntax": true,
      "mx_records": true,
      "disposable": false,
      "role_based": false,
      "free_provider": false,
      "catch_all": false,
      "smtp_valid": null
    },
    "details": {
      "local_part": "john",
      "domain": "company.com",
      "mx_hosts": ["mail.company.com"],
      "suggestion": null
    }
  }
}

Documentation Index

Fetch the complete documentation index at: https://docs.unosend.co/llms.txt

Use this file to discover all available pages before exploring further.

​
Request Body

​
email
string
required
Email address to validate
​
check_smtp
boolean
default:"false"
Perform SMTP mailbox verification. This connects to the mail server to check if the address exists. Slower but more accurate.
​
check_catch_all
boolean
default:"false"
Check if the domain is a catch-all (accepts any email address). Useful for identifying domains where individual addresses can’t be verified.

​
Response

​
email
string
Normalized email address (lowercase)
​
valid
boolean
Whether the email is valid for sending
​
score
number
Quality score from 0-100
​
reason
string
Explanation if email is invalid or risky
​
checks
object
​
details
object
curl -X POST https://api.unosend.co/contacts/validate \
  -H "Authorization: Bearer un_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "john@company.com",
    "check_catch_all": true
  }'

{
  "success": true,
  "data": {
    "email": "john@company.com",
    "valid": true,
    "score": 90,
    "reason": null,
    "checks": {
      "syntax": true,
      "mx_records": true,
      "disposable": false,
      "role_based": false,
      "free_provider": false,
      "catch_all": false,
      "smtp_valid": null
    },
    "details": {
      "local_part": "john",
      "domain": "company.com",
      "mx_hosts": ["mail.company.com"],
      "suggestion": null
    }
  }
}