Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
KMailAssistant - Collaborative email management tool embedded into Outlook.
LiveAgent - LiveAgent is a fully-featured web-based live chat and help desk software. It harnesses the power of a universal inbox, real-time live chat, built-in call center, and a robust customer service portal. Start your free 1 month trial today!
UserEcho - UserEcho gives you the opportunity to create a modern Community to support customers in a few minutes. It includes support forum with the possibility of voting for ideas, Helpdesk, Knowledge Base and Online Chat.
Hiver - Manage Customer Support, Sales and Projects right from your Gmail inbox. Collaborate with Shared Labels, Shared Contacts, email notes, email reminders and email templates
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.