AuthSMTP - AuthSMTP is the outgoing SMTP email service for e-commerce websites, mailing lists or email applications.
Lob - A simple API to integrate print & mail solutions into your applications.
BriteVerify - Email Validation & Email Verification reduces bounce rates up to 98%. Rapidly verifying email addresses has never been easier, just drag drop and deliver!
PostGrid - Transform your Offline Communications. Use our fully-documented REST API to send personalized letters, checks, postcards and improve address accuracy.
CritSend - CritSend is a SMTP relay for developers.
Postalytics - Automated direct mail software that’s faster, smarter & better. Postalytics sends personalized direct mail from your CRM and analyzes delivery & response.