diff --git a/SPECS/postfix/postfix.service b/SPECS/postfix/postfix.service
new file mode 100644
index 0000000000..186414f51f
--- /dev/null
+++ b/SPECS/postfix/postfix.service
@@ -0,0 +1,17 @@
+[Unit]
+Description=Postfix Mail Transport Agent
+After=network.target
+Conflicts=sendmail.service exim.service
+
+[Service]
+Type=forking
+PIDFile=/var/spool/postfix/pid/master.pid
+ExecStartPre=/usr/sbin/postfix check
+ExecStart=/usr/sbin/postfix start
+ExecReload=/usr/sbin/postfix reload
+ExecStop=/usr/sbin/postfix stop
+PrivateTmp=true
+ProtectSystem=full
+
+[Install]
+WantedBy=multi-user.target
diff --git a/SPECS/postfix/postfix.spec b/SPECS/postfix/postfix.spec
new file mode 100644
index 0000000000..8c91d46485
--- /dev/null
+++ b/SPECS/postfix/postfix.spec
@@ -0,0 +1,228 @@
+# SPDX-FileCopyrightText: (C) 2026 Institute of Software, Chinese Academy of Sciences (ISCAS)
+# SPDX-FileCopyrightText: (C) 2026 openRuyi Project Contributors
+# SPDX-FileContributor: Li Guan <guanli.oerv@isrc.iscas.ac.cn>
+#
+# SPDX-License-Identifier: MulanPSL-2.0
+
+%global postfix_user postfix
+%global postdrop_group postdrop
+%global postfix_config_dir %{_sysconfdir}/postfix
+%global postfix_daemon_dir %{_libexecdir}/postfix
+%global postfix_queue_dir %{_var}/spool/postfix
+%global postfix_data_dir %{_var}/lib/postfix
+
+Name:           postfix
+Version:        3.11.5
+Release:        %autorelease
+Summary:        Postfix Mail Transport Agent
+License:        IPL-1.0 OR EPL-2.0
+URL:            https://www.postfix.org/
+# VCS: No VCS link available
+#!RemoteAsset:  sha256:4a6ab3d0e9390989fa201fc6c446045fc702c4e16e7a247c3ae261c9e9bee610
+Source0:        http://ftp.porcupine.org/mirrors/postfix-release/official/postfix-%{version}.tar.gz
+Source1:        postfix.service
+Source2:        postfix.sysusers
+BuildSystem:    autotools
+
+BuildOption(build):  -f Makefile.init
+BuildOption(build):  update
+BuildOption(build):  pie=yes
+BuildOption(build):  shared=no
+BuildOption(build):  dynamicmaps=no
+BuildOption(build):  default_database_type=lmdb
+BuildOption(build):  default_cache_db_type=lmdb
+BuildOption(build):  config_directory=%{postfix_config_dir}
+BuildOption(build):  CCARGS="-DNO_DB -DNO_NIS -DHAS_LDAP -DLDAP_DEPRECATED=1 -DUSE_LDAP_SASL -I%{_includedir}/sasl -DHAS_LMDB -DHAS_PCRE=2 $(pkg-config --cflags libpcre2-8) -DHAS_MYSQL $(pkg-config --cflags libmariadb) -DHAS_PGSQL $(pkg-config --cflags libpq) -DHAS_SQLITE $(pkg-config --cflags sqlite3) -DUSE_SASL_AUTH -DUSE_CYRUS_SASL $(pkg-config --cflags libsasl2) -DUSE_TLS $(pkg-config --cflags openssl)"
+BuildOption(build):  AUXLIBS="$(pkg-config --libs libsasl2 openssl)"
+BuildOption(build):  AUXLIBS_LDAP="$(pkg-config --libs ldap)"
+BuildOption(build):  AUXLIBS_LMDB="$(pkg-config --libs lmdb)"
+BuildOption(build):  AUXLIBS_PCRE="$(pkg-config --libs libpcre2-8)"
+BuildOption(build):  AUXLIBS_MYSQL="$(pkg-config --libs libmariadb)"
+BuildOption(build):  AUXLIBS_PGSQL="$(pkg-config --libs libpq)"
+BuildOption(build):  AUXLIBS_SQLITE="$(pkg-config --libs sqlite3)"
+BuildOption(build):  OPT="%{build_cflags} -fno-strict-aliasing"
+BuildOption(build):  DEBUG=""
+BuildOption(build):  POSTFIX_INSTALL_OPTS=-keep-build-mtime
+
+BuildRequires:  make
+BuildRequires:  m4
+BuildRequires:  pkgconfig(icu-uc)
+BuildRequires:  pkgconfig(ldap)
+BuildRequires:  pkgconfig(libmariadb)
+BuildRequires:  pkgconfig(libpcre2-8)
+BuildRequires:  pkgconfig(libpq)
+BuildRequires:  pkgconfig(libsasl2)
+BuildRequires:  pkgconfig(lmdb)
+BuildRequires:  pkgconfig(openssl)
+BuildRequires:  pkgconfig(sqlite3)
+BuildRequires:  systemd-rpm-macros
+
+Requires:       diffutils
+Requires:       findutils
+Requires(pre):  systemd-sysusers
+Requires(post):  update-alternatives
+Requires(postun):  update-alternatives
+%systemd_requires
+
+Provides:       MTA
+Provides:       smtpdaemon
+
+%description
+Postfix is a mail transport agent that routes and delivers electronic mail.
+It supports SMTP, TLS, SASL, LDAP, SQL, LMDB, and PCRE lookup tables.
+
+%conf
+# Postfix has no configure script; Makefile.init generates its makefiles.
+
+%install
+make non-interactive-package \
+    install_root=%{buildroot} \
+    config_directory=%{postfix_config_dir} \
+    meta_directory=%{postfix_config_dir} \
+    daemon_directory=%{postfix_daemon_dir} \
+    command_directory=%{_sbindir} \
+    queue_directory=%{postfix_queue_dir} \
+    data_directory=%{postfix_data_dir} \
+    sendmail_path=%{_sbindir}/sendmail.postfix \
+    newaliases_path=%{_bindir}/newaliases.postfix \
+    mailq_path=%{_bindir}/mailq.postfix \
+    mail_owner=%{postfix_user} \
+    setgid_group=%{postdrop_group} \
+    manpage_directory=%{_mandir}
+
+for manpage in man1/mailq.1 man1/newaliases.1 man1/sendmail.1 \
+    man5/aliases.5 man8/smtp.8 man8/smtpd.8; do
+    postfix_manpage="${manpage%.*}.postfix.${manpage##*.}"
+    mv "%{buildroot}%{_mandir}/$manpage" \
+        "%{buildroot}%{_mandir}/$postfix_manpage"
+    sed -i "s|^\\.so $manpage$|.so $postfix_manpage|" \
+        %{buildroot}%{_mandir}/man?/*.[1-9]
+    sed -i "s|/$manpage:|/$postfix_manpage:|" \
+        %{buildroot}%{postfix_config_dir}/postfix-files
+done
+
+install -D -m 0644 %{SOURCE1} %{buildroot}%{_unitdir}/postfix.service
+install -D -m 0644 %{SOURCE2} %{buildroot}%{_sysusersdir}/postfix.conf
+
+sed -E -i \
+    -e '\#^\$config_directory/(TLS_)?LICENSE:#d' \
+    -e '\#^\$(html|manpage|readme|sample)_directory[:/]#d' \
+    %{buildroot}%{postfix_config_dir}/postfix-files
+if grep -Eq '^\$config_directory/(TLS_)?LICENSE:|^\$(html|manpage|readme|sample)_directory[:/]' \
+    %{buildroot}%{postfix_config_dir}/postfix-files; then
+    exit 1
+fi
+rm -f %{buildroot}%{postfix_config_dir}/{LICENSE,TLS_LICENSE}
+
+%check
+# Postfix does not provide a check target.
+
+%pre
+%sysusers_create_package %{name} %{SOURCE2}
+
+%post
+%systemd_post postfix.service
+
+if [ "$1" -eq 1 ]; then
+    postfix_post_install_action=set-permissions
+else
+    postfix_post_install_action=upgrade-package
+fi
+
+%{postfix_daemon_dir}/post-install \
+    config_directory=%{postfix_config_dir} \
+    meta_directory=%{postfix_config_dir} \
+    daemon_directory=%{postfix_daemon_dir} \
+    command_directory=%{_sbindir} \
+    queue_directory=%{postfix_queue_dir} \
+    data_directory=%{postfix_data_dir} \
+    mail_owner=%{postfix_user} \
+    setgid_group=%{postdrop_group} \
+    manpage_directory=%{_mandir} \
+    "$postfix_post_install_action" || exit 1
+
+update-alternatives --install \
+    /usr/sbin/sendmail mta %{_sbindir}/sendmail.postfix 60 \
+    --slave %{_bindir}/mailq mta-mailq %{_bindir}/mailq.postfix \
+    --slave %{_bindir}/newaliases mta-newaliases %{_bindir}/newaliases.postfix \
+    --slave %{_mandir}/man1/mailq.1.gz mta-mailqman %{_mandir}/man1/mailq.postfix.1.gz \
+    --slave %{_mandir}/man1/newaliases.1.gz mta-newaliasesman %{_mandir}/man1/newaliases.postfix.1.gz \
+    --slave %{_mandir}/man8/sendmail.8.gz mta-sendmailman %{_mandir}/man1/sendmail.postfix.1.gz \
+    --slave %{_mandir}/man5/aliases.5.gz mta-aliasesman %{_mandir}/man5/aliases.postfix.5.gz \
+    --slave %{_mandir}/man8/smtp.8.gz mta-smtpman %{_mandir}/man8/smtp.postfix.8.gz \
+    --slave %{_mandir}/man8/smtpd.8.gz mta-smtpdman %{_mandir}/man8/smtpd.postfix.8.gz \
+    >/dev/null || exit 1
+
+%preun
+%systemd_preun postfix.service
+
+%postun
+%systemd_postun_with_restart postfix.service
+
+if [ "$1" -eq 0 ]; then
+    mta_current=$(readlink %{_sysconfdir}/alternatives/mta 2>/dev/null || :)
+    update-alternatives --remove mta %{_sbindir}/sendmail.postfix \
+        >/dev/null 2>&1 || :
+    if [ -n "$mta_current" ] &&
+        [ "$mta_current" != "%{_sbindir}/sendmail.postfix" ]; then
+        update-alternatives --set mta "$mta_current" \
+            >/dev/null 2>&1 || :
+    fi
+fi
+
+%files
+%doc COMPATIBILITY HISTORY README_FILES RELEASE_NOTES TLS_ACKNOWLEDGEMENTS
+%license LICENSE TLS_LICENSE
+%dir %{postfix_config_dir}
+%config(noreplace) %{postfix_config_dir}/access
+%config(noreplace) %{postfix_config_dir}/aliases
+%{postfix_config_dir}/bounce.cf.default
+%config(noreplace) %{postfix_config_dir}/canonical
+%config(noreplace) %{postfix_config_dir}/generic
+%config(noreplace) %{postfix_config_dir}/header_checks
+%config(noreplace) %{postfix_config_dir}/main.cf
+%{postfix_config_dir}/main.cf.default
+%{postfix_config_dir}/main.cf.proto
+%{postfix_config_dir}/makedefs.out
+%config(noreplace) %{postfix_config_dir}/master.cf
+%{postfix_config_dir}/master.cf.proto
+%{postfix_config_dir}/postfix-files
+%dir %{postfix_config_dir}/postfix-files.d
+%config(noreplace) %{postfix_config_dir}/relocated
+%config(noreplace) %{postfix_config_dir}/transport
+%config(noreplace) %{postfix_config_dir}/virtual
+%{_bindir}/mailq.postfix
+%{_bindir}/newaliases.postfix
+%{_sbindir}/postalias
+%{_sbindir}/postcat
+%{_sbindir}/postconf
+%attr(2755, root, %{postdrop_group}) %{_sbindir}/postdrop
+%{_sbindir}/postfix
+%{_sbindir}/postkick
+%{_sbindir}/postlock
+%attr(2755, root, %{postdrop_group}) %{_sbindir}/postlog
+%{_sbindir}/postmap
+%{_sbindir}/postmulti
+%attr(2755, root, %{postdrop_group}) %{_sbindir}/postqueue
+%{_sbindir}/postsuper
+%{_sbindir}/sendmail.postfix
+%{postfix_daemon_dir}
+%{_mandir}/man1/*
+%{_mandir}/man5/*
+%{_mandir}/man8/*
+%{_unitdir}/postfix.service
+%{_sysusersdir}/postfix.conf
+%ghost /usr/sbin/sendmail
+%ghost %{_bindir}/mailq
+%ghost %{_bindir}/newaliases
+%ghost %{_mandir}/man1/mailq.1.gz
+%ghost %{_mandir}/man1/newaliases.1.gz
+%ghost %{_mandir}/man5/aliases.5.gz
+%ghost %{_mandir}/man8/sendmail.8.gz
+%ghost %{_mandir}/man8/smtp.8.gz
+%ghost %{_mandir}/man8/smtpd.8.gz
+%ghost %dir %attr(0700, %{postfix_user}, root) %{postfix_data_dir}
+%ghost %dir %{postfix_queue_dir}
+
+%changelog
+%autochangelog
diff --git a/SPECS/postfix/postfix.sysusers b/SPECS/postfix/postfix.sysusers
new file mode 100644
index 0000000000..00fd5842f9
--- /dev/null
+++ b/SPECS/postfix/postfix.sysusers
@@ -0,0 +1,3 @@
+u postfix 89 "Postfix mail system" /var/spool/postfix /usr/sbin/nologin
+g postdrop 90
+m postfix mail