Spam filter.

[spwbot]

I suggest making it possible add some kind of Spam filter or email filter system. For accounts with to much spam is not possible use Roundcube. I am talking about account wiht 150 junk emails per day.
I think this is VERY needed.

[dogcow]

It may be, but Roundcube is just a web client. You're just supposed to use Roundcube to read your emails and send them, not do everything else!

[jpingle]

While it is nice to do the spam filtering at the MTA level, some people aren't lucky enough to have that kind of control.

This is something that a third-party could work on once a plugin system is in place, but I wouldn't say it is so important that it's required to be in the base system.

[spwbot]

Well, i think a simply filter could be good.
Not something like a complete spam filter, but something to hunt some spam from the messege subject or something like that.