Hi! I work with customer support and I have to constantly check and respond from 5 different email addresses. I need to be able to have 5 different signatures depending on which email I write from. I need to be able to use pre-written templates with information that we usually give our customers about our services/prices. I need advanced filtering and sorting options. And most importantly, it need to be 100% online. No downloads required. I need to be able to access this client from any computer at any time. Pleasae help. What is the most powerful online email client out there? It does not have to be free!