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

Calculating dependencies ... done!
Dependency resolution took 1.67 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/geoip-1.6.12-r1::gentoo  USE="-static-libs" 158 KiB
[ebuild  N     ] sys-libs/tdb-1.4.15::gentoo  USE="python -test" PYTHON_SINGLE_TARGET="python3_14 -python3_12 -python3_13" 736 KiB
[ebuild  N     ] mail-mta/exim-4.100.1::gentoo  USE="dane dkim dlfunc dmarc-opendmarc dnsdb gdbm pkcs11 prdr proxy sqlite ssl tdb tpda -arc -berkdb -dcc -dmarc -dmarc-native -doc -dovecot-sasl -dsn -gnutls -gsasl -idn -ldap -lmtp -maildir -mbx -mysql -nis (-pam) -perl -postgres -redis -sasl (-selinux) -socks5 -spf -srs -syslog -tcpd" 1964 KiB
[uninstall     ] mail-mta/nullmailer-2.2-r2::gentoo  USE="ssl -test" 
[blocks b      ] mail-mta/exim ("mail-mta/exim" is soft blocking mail-mta/nullmailer-2.2-r2)
[blocks b      ] mail-mta/nullmailer ("mail-mta/nullmailer" is soft blocking mail-mta/exim-4.100.1)
[ebuild  N     ] mail-filter/exim-geoip-0.1-r1::gentoo  300 KiB

Total: 4 packages (4 new, 1 uninstall), Size of downloads: 3156 KiB
Conflict: 2 blocks (all satisfied)

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by mail-filter/exim-geoip-0.1-r1::gentoo
# required by =mail-filter/exim-geoip-0.1-r1 (argument)
>=mail-mta/exim-4.100.1 dlfunc