I'm running Debian/Buster on an AMD64 system.When I use "mail" to send e-mail from the command line, it doesn't use /etc/email-addresses to rewrite the "from" header but s-nail does.
Apparently on my system, mail is provided by the Gnu Mailutils. Is the the normal behaviour for Mailutils or do I have to configure it to respect /etc/email-addresses?