These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] net-libs/courier-unicode-2.3.2:0/7::gentoo  643 KiB
[ebuild  N     ] net-mail/courier-common-3.3.0::gentoo  USE="gdbm -berkdb" 2387 KiB
[ebuild  N     ] mail-filter/maildrop-3.1.8-r1::gentoo  USE="gdbm tools -authlib -berkdb -debug -dovecot -ldap -mysql -postgres -static-libs -trashquota" 2106 KiB

Total: 3 packages (3 new), Size of downloads: 5136 KiB