mount and umount large capacity external USB HDD (fstab)

[freebsd_user at guice.ath.cx]

Hope we are posting to the correct list ...

We’re using a laptop for our temp mail-server and would like to attach a
two (2) or three (3) TB external USB HDD for back-up purposes.  Would
someone be kind enough to point us to a step-by-step article on what needs
to be entered in the /etc/fstab to allow us to leave the drive connected
and facilitate auto mount/umount across system reboots; the results Google
are presenting isn’t sufficient.  Perhaps it’s or search terms that aren’t
on point.

Thanks.