Webmail means a web application where user can login into his mail box read mail and send to others. Its a convenient way to access mail box when your personal computer is not with you because you can access from anywhere.
In shared hosting webmails most of the provoders are giving three options like Horde , RoundCube and SquirrelMail.
In squirrel mail has all the basic email client features like adress book, spell check etc.,
Roundcube has more better User interface and more added features like editing in html format etc.,
Horde comes with all the features mentioned in above two and this email management system have advanced filters, email attachment, last login location or internet provider name for security purpose.
So what email viewer you mostly prefer to use?