214 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 firstname.lastname@example.org and email@example.com and firstname.lastname@example.org 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.