Abstract Email Validation API vs CaptainVerify

Abstract Email Validation API checks whether submitted email addresses are correctly formed and can receive mail. One call checks address format, domain MX records, live SMTP without sending a message, and disposable or catch-all addresses. Responses arrive as structured JSON with deliverability, a quality score, SMTP status, and MX validation. The API supports signup form cleanup, B2B lead verification, and efforts to reduce bounce rates without tying a developer to one email provider. The product page says real-time validation responses arrive in under 300ms, and the API also supports bulk checks. CSV upload is included with listed paid plans. The Free plan includes 100 requests at three requests per second. Starter is $17 a month, billed annually, with 60,000 requests per year, three requests per second, domain whitelisting, and bulk CSV upload. The listed integrations include HubSpot, AWS, Salesforce, Zapier, Snowflake, Shopify, Make, Mailchimp, and Azure. The product page lists a 99.99% uptime SLA and describes privacy protections and compliance resources.

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