Ability to apply mail filters to existing messages in the Inbox
It would be very helpful to be able to have the option to apply mail filters to existing messages in the Inbox.
Gmail apparently has this feature and several clients have mentioned to me that they really liked having this ability when using Gmail. I don't want to lose out on clients just because Gmail's UI is a few steps ahead.
Love this idea! No plans to do this in the near future, but this feature will remain open for voting.
James Hume commented
I used to use a feature like this a lot in Thunderbird when I had a large inbox.