$ emerge -a smartmontools
These are the packages that would be merged, in order:
Calculating dependencies... done!
[ebuild N ] net-mail/mailutils-2.99.98 USE="berkdb clients gdbm ipv6 ldap mysql nls pam python ssl tcpd threads -bidi -guile -kerberos -postgres -sasl -servers -static-libs -tokyocabinet"
[ebuild N ] virtual/mailx-1
[ebuild N ] sys-apps/smartmontools-6.4 USE="-caps -minimal (-selinux) -static"