Google Gmail

Google's Gmail is one of the best webmail provides out there! They have packed it full of features that other companies restrict from you. Support for IMAP, POP, forward your emails, signature, create custom labels to catagorize your mail, create filters to automatically move mail as its recieved, custom themes, offline mail support, even setup to send email from your other email accounts. When it comes to Gmail its packed with the features your looking for that others dont offer!

http://www.gmail.com