There’s a lot of sieve extensions available to help with incoming mail processing. Managesieve plugin for Roundcube provides a nice user interface to manage your scripts and supports a lot of existing extensions. Recently I added support for another one: editheader.
The extension describes two additional actions that add ways to manipulate message headers. You can add headers to the message…
…and you can remove them. As simple as that. There are also some additional options, so there’s more control. You can remove a header depending on a pattern or its position/occurrence.
Sounds much like a feature for power-users only, but nice to have anyway.