rapidmail VS ZeroBounce

Mailjet - All-in-one email service provider that provides maximum insight and deliverability results for both marketing and transactional emails.

NeverBounce - Real-time email verification and cleaning to ensure emails never bounce.

Brevo - Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.

Email List Verify - The Fastest Way to Improve Email List Deliverability and ROI

PHPMailer - Email sending library for PHP.

DeBounce - Email Validation, Email Checker, Data Enrichment and Appending Tool. Using DeBounce remove invalid, disposable, spam-trap, syntax and deactivated emails.