Roundcube has a beautiful simplicity about its interface. It depends heavily on modern browsers, so I worry a little about its performance on smaller devices. But still, it really is a refreshing change from large clunky interfaces.
The problem with PHP webmail (or with my mail server, depending on your point of view) is that is uses the login name as the sender email address, usually. My logins are mailbox names, not email addresses. Lots of email addresses resolve down to a single mailbox…. At first I saw this as a fault with the web mail software, but came to realize that it was more a limitation of the mail server, as I had configured it. A mailbox id currently is maildir@account, which does look like an email, i’ll give you that… So, I am going to change it firstly so that the mailbox format is maildir%account, but also so that people CAN authenticate with any valid email address that maps to that mailbox.
The Register