When emerging sendmail in a out-of-the-box gentoo installation: These are the packages that I would merge, in order. Calculating dependencies !!! Error merging /usr/portage/net- mail/sendmail/sendmail-8.12.4-r2.ebuild: invalid dependency in: 'net-dns/hesiod sys-libs/gdbm sys-devel/m4 sasl? ( dev-libs/cyrus-sasl ) tcpd? ( sys-apps/tcp-wrappers ) ssl? ( dev-libs/openssl ) ldap? ( net-nds/openldap ) sys-libs/db-3.2 net-dns/hesiod sys-libs/gdbm sys-devel/m4 sasl? ( dev- libs/cyrus-sasl ) tcpd? ( sys-apps/tcp-wrappers ) ssl? ( dev-libs/openssl ) ldap? ( net-nds/openldap ) sys-libs/db-3.2 >=net-mail/mailbase-0.00 ! virtual/mta' >>> Please report this ebuild error to http://bugs.gentoo.org.
Weird. I did a test bootstrap + emerge system earlier today in a chroot, and running emerge sendmail in that chroot works just fine for me. What do you have in USE? What version of portage are you using? You might try 'rm -rf /var/cache/edb/dep/*', then see if you can emerge sendmail.
Closing, since I haven't heard anything back in ten days.