diff --git a/pkgs/by-name/sy/sylpheed/package.nix b/pkgs/by-name/sy/sylpheed/package.nix
deleted file mode 100644
index 218de628020e..000000000000
--- a/pkgs/by-name/sy/sylpheed/package.nix
+++ /dev/null
@@ -1,69 +0,0 @@
-{
-  lib,
-  stdenv,
-  fetchurl,
-  pkg-config,
-  gtk2,
-  openssl ? null,
-  gpgme ? null,
-  gpgSupport ? true,
-  sslSupport ? true,
-  fetchpatch,
-}:
-
-assert gpgSupport -> gpgme != null;
-assert sslSupport -> openssl != null;
-
-stdenv.mkDerivation (finalAttrs: {
-  pname = "sylpheed";
-  version = "3.7.0";
-
-  src = fetchurl {
-    url = "https://sylpheed.sraoss.jp/sylpheed/v3.7/sylpheed-${finalAttrs.version}.tar.xz";
-    sha256 = "0j9y5vdzch251s264diw9clrn88dn20bqqkwfmis9l7m8vmwasqd";
-  };
-
-  patches = [
-    (fetchpatch {
-      # patch upstream bug https://sylpheed.sraoss.jp/redmine/issues/306
-      name = "patch-libsylph_ssl_c.patch";
-      extraPrefix = "";
-      url = "https://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/ports/mail/sylpheed/patches/patch-libsylph_ssl_c?rev=1.4&content-type=text/plain";
-      sha256 = "sha256-+FetU5vrfvE78nYAjKK/QFZnFw+Zr2PvoUGRWCuZczs=";
-    })
-    (fetchpatch {
-      name = "CVE-2021-37746.patch";
-      url = "https://git.claws-mail.org/?p=claws.git;a=patch;h=ac286a71ed78429e16c612161251b9ea90ccd431";
-      sha256 = "sha256-oLmUShtvO6io3jibKT67eO0O58vEDZEeaB51QTd3UkU=";
-    })
-    (fetchurl {
-      name = "0013-fix-FTBFS-GCC-14.patch";
-      url = "https://salsa.debian.org/sylpheed-team/sylpheed/-/raw/22984c6d2bf76b0667256a9e8b660447497e1220/debian/patches/0013-fix-FTBFS-GCC-14.patch?inline=false";
-      sha256 = "sha256-ZfQKiOK8pMrN87hrP0/2LxYZZdnaciBoa0khG1Djelo=";
-    })
-  ];
-
-  nativeBuildInputs = [ pkg-config ];
-
-  buildInputs = [
-    gtk2
-  ]
-  ++ lib.optionals gpgSupport [ gpgme ]
-  ++ lib.optionals sslSupport [ openssl ];
-
-  configureFlags = lib.optional gpgSupport "--enable-gpgme" ++ lib.optional sslSupport "--enable-ssl";
-
-  # Undefined symbols for architecture arm64: "_OBJC_CLASS_$_NSAutoreleasePool"
-  env = lib.optionalAttrs stdenv.hostPlatform.isDarwin {
-    NIX_LDFLAGS = "-framework Foundation";
-  };
-
-  meta = {
-    homepage = "https://sylpheed.sraoss.jp/en/";
-    description = "Lightweight and user-friendly e-mail client";
-    mainProgram = "sylpheed";
-    maintainers = [ ];
-    platforms = lib.platforms.linux ++ lib.platforms.darwin;
-    license = lib.licenses.gpl2;
-  };
-})
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index 86ff9d86da7a..a3e33ec63bd0 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -1925,6 +1925,7 @@ mapAliases {
   swiPrologWithGui = throw "'swiPrologWithGui' has been renamed to/replaced by 'swi-prolog-gui'"; # Converted to throw 2025-10-27
   swww = warnAlias "'swww' has been renamed to 'awww'" awww; # Added 2026-03-22
   Sylk = throw "'Sylk' has been renamed to/replaced by 'sylk'"; # Converted to throw 2025-10-27
+  sylpheed = throw "'sylpheed' has been removed because it is broken and unmaintained, please use 'claws-mail' instead"; # Added 2026-04-22
   symbiyosys = throw "'symbiyosys' has been renamed to/replaced by 'sby'"; # Converted to throw 2025-10-27
   syn2mas = throw "'syn2mas' has been removed. It has been integrated into the main matrix-authentication-service CLI as a subcommand: 'mas-cli syn2mas'."; # Added 2025-07-07
   synapse-admin-etkecc = warnAlias "'synapse-admin-etkecc' has been renamed to 'ketesa'" ketesa; # Added 2026-04-03