Xobni

Xobni, the word “inbox” spelled backwards, is a free Outlook add-on application.  While Xobni’s core talent lays in rapidly finding e-mails and contacts based on any keyword search, it also excels at surfacing meetings and file attachments, hyperlinks, and even personal information extracted from social networks, like photos and phone numbers.

Shortmail

Shortmail is an entirely new email service that restricts email messages to 500 characters, which encourages conciseness. It also enables radically new features like Public Conversations, and better integration with social channels.  It is a new way to communicate.

IncrediMail

IncrediMail provides a serial of email related products. It’s fun.

Digsby

Digsby is a free software product that helps you manage all your IM, email, and social network accounts from one easy-to-use application.

WiseStamp

WiseStamp is an email app that allows usrs to bring functionality in every email they send. It has been awarded as the Best Social Media Gadget by Mashable’s 3RD Annual Open Web Awards 2009.

Melissa Data

Melissa Data provides support of scalable developer tools, mailing software, direct marketing programs, data hygiene and enhancement services, mailing lists, and information of products and services available on the market today.