There used to be an addon that would redirect via filter, but that was a few years back.

Thanks I did find that but I was looking for a solution for the current thunderbird version - it's pretty standard in most e-mail client rules/filters.

I think this may be the addon you require: https://addons.thunderbird.net/en-us/thunderbird/addon/simple-mail-redirection/

Is that addon useful, since Redirect is now part of Thunderbird? I don't see how he will use it with a filter.

Is that addon useful, since Redirect is now part of Thunderbird? I don't see how he will use it with a filter.

Good point - you are correct. Forgot it was now incorporated in right click menu or via 'More' menu.

It's more complicated than a simple forward, because a forward just needs to know who to forward to. A Redirect needs to read headers create a Reply-to original sender and also have the Forward to information.

Thanks the simple redirection add-on also works in mail filters I've tried it and you can redirect to multiple recipients I just seperate each e-mail with a comma

Thanks for sharing that. I didn't know, but now I can share with others. Much appreciated.