Can GNU mailutils add an "unread" command for mailx, similar to what BSD mailx has? [1] [2] This would allow using GNU mailutils to mark emails as "unread".
[1]: https://man.openbsd.org/mail [2]: https://www.freebsd.org/cgi/man.cgi?query=mailx&manpath=FreeBSD+13.0-RELEASE
