diff --git a/.github/codecov.yml b/.github/codecov.yml
new file mode 100644
index 0000000..ff4f571
--- /dev/null
+++ b/.github/codecov.yml
@@ -0,0 +1,21 @@
+# ref: https://docs.codecov.com/docs/codecovyml-reference
+coverage:
+  # Hold ourselves to a high bar
+  range: 85..100
+  round: down
+  precision: 1
+  status:
+    # ref: https://docs.codecov.com/docs/commit-status
+    project:
+      default:
+        # Avoid false negatives
+        threshold: 1%
+
+# Test files aren't important for coverage
+ignore:
+  - "tests"
+
+# Make comments less noisy
+comment:
+  layout: "files"
+  require_changes: yes
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index b38f6e1..e9a9358 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -1,34 +1,34 @@
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
 name: coverage
 jobs:
   test:
     runs-on: ubuntu-latest
-    container:
-      image: xd009642/tarpaulin
-      options: --security-opt seccomp=unconfined
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+          components: llvm-tools-preview
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
       - name: Generate code coverage
-        run: |
-          cargo tarpaulin --verbose --timeout 120 --out Xml
-        env:
-          TEST_HOST: greenmail
+        run: cargo llvm-cov --features test-full-imap --lcov --output-path lcov.info
       - name: Upload to codecov.io
         uses: codecov/codecov-action@v2
         with:
           fail_ci_if_error: true
     services:
-      greenmail:
-        image: greenmail/standalone:1.6.8
+      cyrus_imapd:
+        image: outoforder/cyrus-imapd-tester:latest
         ports:
-          - 3025:3025
-          - 3110:3110
-          - 3143:3143
-          - 3465:3465
-          - 3993:3993
-          - 3995:3995
-        env:
-          GREENMAIL_OPTS: "-Dgreenmail.setup.test.all -Dgreenmail.hostname=0.0.0.0 -Dgreenmail.auth.disabled -Dgreenmail.verbose"
+          - 3025:25
+          - 3143:143
+          - 3465:465
+          - 3993:993
diff --git a/.github/workflows/features.yml b/.github/workflows/features.yml
index dd787cb..ac5e18e 100644
--- a/.github/workflows/features.yml
+++ b/.github/workflows/features.yml
@@ -1,6 +1,6 @@
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
 name: cargo hack
 jobs:
@@ -11,13 +11,11 @@ jobs:
         with:
           profile: minimal
           toolchain: stable
-      - uses: actions/checkout@v2
-      - name: Install cargo-hack
-        uses: actions-rs/install@v0.1
+      - uses: actions/checkout@v3
         with:
-          crate: cargo-hack
-          version: latest
-          use-tool-cache: true
+          submodules: true
+      - name: Install cargo-hack
+        uses: taiki-e/install-action@cargo-hack
       - name: cargo hack
         uses: actions-rs/cargo@v1
         with:
diff --git a/.github/workflows/minimal.yml b/.github/workflows/minimal.yml
index 4ea4722..9a3f187 100644
--- a/.github/workflows/minimal.yml
+++ b/.github/workflows/minimal.yml
@@ -1,6 +1,6 @@
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
 name: With dependencies at minimal versions
 jobs:
@@ -15,7 +15,9 @@ jobs:
         with:
           profile: minimal
           toolchain: stable
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: cargo update -Zminimal-versions
         uses: actions-rs/cargo@v1
         with:
@@ -26,15 +28,12 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: test
+          args: --features test-full-imap --all-targets
     services:
-      greenmail:
-        image: greenmail/standalone:1.6.8
+      cyrus_imapd:
+        image: outoforder/cyrus-imapd-tester:latest
         ports:
-          - 3025:3025
-          - 3110:3110
-          - 3143:3143
-          - 3465:3465
-          - 3993:3993
-          - 3995:3995
-        env:
-          GREENMAIL_OPTS: "-Dgreenmail.setup.test.all -Dgreenmail.hostname=0.0.0.0 -Dgreenmail.auth.disabled -Dgreenmail.verbose"
+          - 3025:25
+          - 3143:143
+          - 3465:465
+          - 3993:993
diff --git a/.github/workflows/msrv.yml b/.github/workflows/msrv.yml
index ee1b2bf..d6d9046 100644
--- a/.github/workflows/msrv.yml
+++ b/.github/workflows/msrv.yml
@@ -1,6 +1,6 @@
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
 name: Minimum Supported Rust Version
 jobs:
@@ -10,10 +10,12 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: 1.56.0 # 2021 edition requires 1.56
+          toolchain: 1.56.1 # 2021 edition requires 1.56
           override: true
-      - uses: actions/checkout@v2
-      - name: cargo +1.56.0 check
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
+      - name: cargo +1.56.1 check
         uses: actions-rs/cargo@v1
         with:
           command: check
diff --git a/.github/workflows/os-check.yml b/.github/workflows/os-check.yml
index bbcb475..1054489 100644
--- a/.github/workflows/os-check.yml
+++ b/.github/workflows/os-check.yml
@@ -1,8 +1,8 @@
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
-name: cargo check
+name: os check
 jobs:
   os-check:
     runs-on: ${{ matrix.os }}
@@ -16,7 +16,7 @@ jobs:
         with:
           profile: minimal
           toolchain: stable
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: cargo check
         uses: actions-rs/cargo@v1
         with:
diff --git a/.github/workflows/style.yml b/.github/workflows/style.yml
index 34c058e..7a583f2 100644
--- a/.github/workflows/style.yml
+++ b/.github/workflows/style.yml
@@ -1,6 +1,6 @@
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
 name: lint
 jobs:
@@ -17,20 +17,32 @@ jobs:
           profile: minimal
           toolchain: ${{ matrix.toolchain }}
           components: rustfmt, clippy
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: cargo fmt --check
         uses: actions-rs/cargo@v1
         with:
           command: fmt
           args: --check
-      - name: cargo doc
-        uses: actions-rs/cargo@v1
-        if: always()
-        with:
-          command: doc
-          args: --no-deps --all-features
       - name: cargo clippy
         uses: actions-rs/clippy-check@v1
         if: always()
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
+  doc:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: nightly
+      - uses: actions/checkout@v3
+      - name: cargo doc
+        uses: actions-rs/cargo@v1
+        with:
+          toolchain: nightly
+          command: doc
+          args: --no-deps --all-features
+        env:
+          RUSTDOCFLAGS: --cfg docsrs
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c96579b..3821afd 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,6 +1,6 @@
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
 name: cargo test
 jobs:
@@ -15,11 +15,14 @@ jobs:
         with:
           profile: minimal
           toolchain: ${{ matrix.toolchain }}
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: cargo test
         uses: actions-rs/cargo@v1
         with:
           command: test
+          args: --all-targets
     services:
       greenmail:
         image: greenmail/standalone:1.6.8
@@ -43,12 +46,14 @@ jobs:
         with:
           profile: minimal
           toolchain: ${{ matrix.toolchain }}
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: cargo test
         uses: actions-rs/cargo@v1
         with:
           command: test
-          args: --features test-full-imap
+          args: --features test-full-imap --all-targets
     services:
       cyrus_imapd:
         image: outoforder/cyrus-imapd-tester:latest
diff --git a/src/lib.rs b/src/lib.rs
index 3860474..b9c19ba 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -75,6 +75,7 @@
 //! for a working example.
 #![deny(missing_docs)]
 #![warn(rust_2018_idioms)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 mod parse;