FabioLolix [1] filed a deletion request for instantbird [2]: Deprecated since many years now http://blog.queze.net/post/2017/10/18/Thunderbird-is-the-next-version- of-Instantbird, this work only with a specific version of xulrunner (v25) which isn't available [1] https://aur.archlinux.org/account/FabioLolix/ [2] https://aur.archlinux.org/pkgbase/instantbird/