$ man mail

SEE ALSO

The complete GNU mailutils documentation is maintained as a Texinfo manual. If the mailutils-doc package is installed, the command

info mailutils

should give you access to the complete manual.

$ info mailutils

-bash: info: command not found

$ uname -mor

6.12.20+rpt-rpi-v8 aarch64 GNU/Linux

$ wget https://download.freebsd.org/releases/arm64/aarch64/ISO-IMAGES/14.3/FreeBSD-14.3-RELEASE-arm64-aarch64-RPI.img.xz