Install this version:
emerge -a =dev-perl/Net-SMTP-TLS-ButMaintained-0.240.0
If this version is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask =dev-perl/Net-SMTP-TLS-ButMaintained-0.240.0
Or alternatively:
emerge --autounmask-write -a =dev-perl/Net-SMTP-TLS-ButMaintained-0.240.0
# Copyright 1999-2021 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
EAPI=8
DIST_AUTHOR=FAYLAND
DIST_VERSION=0.24
inherit perl-module
DESCRIPTION="An SMTP client supporting TLS and AUTH"
SLOT="0"
KEYWORDS="~amd64 ~x86"
RDEPEND="
virtual/perl-IO
virtual/perl-libnet
>=dev-perl/IO-Socket-SSL-1.760.0
dev-perl/Net-SSLeay
virtual/perl-MIME-Base64
dev-perl/Digest-HMAC
"
BDEPEND="${RDEPEND}
>=virtual/perl-ExtUtils-MakeMaker-6.300.0
"
virtual/perl-IO virtual/perl-libnet >=dev-perl/IO-Socket-SSL-1.760.0 dev-perl/Net-SSLeay virtual/perl-MIME-Base64 dev-perl/Digest-HMAC
virtual/perl-IO virtual/perl-libnet >=dev-perl/IO-Socket-SSL-1.760.0 dev-perl/Net-SSLeay virtual/perl-MIME-Base64 dev-perl/Digest-HMAC >=virtual/perl-ExtUtils-MakeMaker-6.300.0