The way emails can be filtered and assigned to different folders within evolution is not very convenient.
The process of filtering messages by subject, address etc. only is quite inflexible and boring.
In the past, i worked with Opera for a long time, by now chose to stick to the given and integrated features within Ubuntu.
As Opera does have no calendar and task features, Evolution would be a really nice alternative, if the email filtering wasn't that outdated in comparison to Opera.
In Opera, you can create email folders and give them the ability to "learn" from the messages added and removed, similar to the already existing spam filter, but here individually for the context of your choice.
After a while and some training, the filters work like a charm and make it so much easier to sort and resort your emails.
For example, after a while the filters even recognise if the mail from a colleague belong to a project or are of personal nature and accordingly shows it within the according folder.
That's a feature i really badly miss within Evolution and which would make it a really productive tool for me.