218 votesRuud Voost commented
This! Automatic tagging would be awesome as well. E.g. lots of mails from multiple people at one company would have the tag of that company this way one would have email@example.com and firstname.lastname@example.org and email@example.com result in a tag "client". Tags should show up in a single line, and easily editable without right clicking or anything, just click and type.