diff --git a/filtermail/.github/workflows/ci.yml b/filtermail/.github/workflows/ci.yml
new file mode 100644
index 00000000..1d692c23
--- /dev/null
+++ b/filtermail/.github/workflows/ci.yml
@@ -0,0 +1,77 @@
+name: CI
+
+permissions: {}
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  fmt:
+    name: Check Formatting
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - uses: dtolnay/rust-toolchain@6d653acede28d24f02e3cd41383119e8b1b35921 # master
+        with:
+          toolchain: nightly
+          components: rustfmt
+      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2
+      - uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
+        with:
+          tool: taplo-cli
+      - run: taplo format --check && cargo fmt --check
+
+  cargo-machete:
+    name: Check Unused Dependencies
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - uses: bnjbvr/cargo-machete@7959c845782fed02ee69303126d4a12d64f1db18 # v0.9.1
+
+  lint-clippy:
+    name: Check Clippy
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        toolchain: ["stable", "beta"]
+    continue-on-error: ${{ matrix.toolchain == 'beta' }}
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - uses: dtolnay/rust-toolchain@6d653acede28d24f02e3cd41383119e8b1b35921 # master
+        with:
+          toolchain: ${{ matrix.toolchain }}
+          components: clippy
+      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2
+      - run: cargo clippy
+        env:
+          RUSTUP_TOOLCHAIN: ${{ matrix.toolchain }}
+
+  test:
+    name: Test on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - uses: dtolnay/rust-toolchain@6d653acede28d24f02e3cd41383119e8b1b35921 # master
+        with:
+          toolchain: stable
+      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2
+      - run: cargo test