HEY - Email at its best, new from Basecamp.
NeverBounce - Real-time email verification and cleaning to ensure emails never bounce.
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
Email List Verify - The Fastest Way to Improve Email List Deliverability and ROI
InstAddr - Disposable email address application.
clearout.io - Clearout Email Finder & Email Verification Service - Drive sustainable business growth by expanding your reach, lowering hard bounces, and improving deliverability rates.