diff --git a/.github/workflows/build-php-exts-windows.yml b/.github/workflows/build-php-exts-windows.yml
index c6e04b4..325869e 100644
--- a/.github/workflows/build-php-exts-windows.yml
+++ b/.github/workflows/build-php-exts-windows.yml
@@ -7,6 +7,8 @@
 #                version as "@PACKAGE_VERSION@" on Windows, as in the imagick maintainers' own
 #                Windows DLLs.
 #   mongodb      the MongoDB maintainers' own signed DLLs (PHP 8.1+), checked against GitHub's SHA-256
+#   imap         the PHP team's PECL DLLs (PHP 8.4+; the official builds have it up to 8.3), checked
+#                against the SHA-256 pinned in php.windows.extensions.imap
 # Published as php-exts-<minor>-build<N>-windows-x64.zip on the php-exts-<minor> release:
 #   ext/php_<name>.dll   the extensions
 #   *.dll                libraries they need next to php.exe (ImageMagick's for imagick)
diff --git a/.github/workflows/build-php-linux.yml b/.github/workflows/build-php-linux.yml
index ea5f961..a37b5c7 100644
--- a/.github/workflows/build-php-linux.yml
+++ b/.github/workflows/build-php-linux.yml
@@ -72,7 +72,9 @@ jobs:
       - name: Read versions.json
         id: config
         run: |
-          jq -r '.php.linux | "SPC_VERSION=\(.spc)\nSTATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions)"' versions.json >> "$GITHUB_ENV"
+          # FrankenPHP (ZTS) leaves out frankenphp.skip_extensions: imap isn't thread-safe.
+          jq -r --arg pkg "$PKG" '(if $pkg == "frankenphp" then (.frankenphp.skip_extensions // "") | split(",") else [] end) as $skip
+            | .php.linux | "SPC_VERSION=\(.spc)\nSTATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions | split(",") - $skip | join(","))"' versions.json >> "$GITHUB_ENV"
           echo "MINOR=$(cut -d. -f1-2 <<<"$VERSION")" >> "$GITHUB_ENV"
           case "$PKG" in
             php) build="$(jq -r .php.linux.build versions.json)" ;;
@@ -145,7 +147,9 @@ jobs:
         with:
           name: ${{ env.ASSET }}
       - name: Read versions.json
-        run: jq -r '.php.linux | "STATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions)"' versions.json >> "$GITHUB_ENV"
+        run: |
+          jq -r --arg pkg "$PKG" '(if $pkg == "frankenphp" then (.frankenphp.skip_extensions // "") | split(",") else [] end) as $skip
+            | .php.linux | "STATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions | split(",") - $skip | join(","))"' versions.json >> "$GITHUB_ENV"
       - name: Smoke test
         run: |
           mkdir pkg && tar -C pkg -xzf "$ASSET"
diff --git a/.github/workflows/build-php-macos.yml b/.github/workflows/build-php-macos.yml
index b941bb5..e48324a 100644
--- a/.github/workflows/build-php-macos.yml
+++ b/.github/workflows/build-php-macos.yml
@@ -63,7 +63,9 @@ jobs:
       - name: Read versions.json
         id: config
         run: |
-          jq -r '.php.macos | "SPC_VERSION=\(.spc)\nMIN_OS=\(.min_os)\nSTATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions)"' versions.json >> "$GITHUB_ENV"
+          # FrankenPHP (ZTS) leaves out frankenphp.skip_extensions: imap isn't thread-safe.
+          jq -r --arg pkg "$PKG" '(if $pkg == "frankenphp" then (.frankenphp.skip_extensions // "") | split(",") else [] end) as $skip
+            | .php.macos | "SPC_VERSION=\(.spc)\nMIN_OS=\(.min_os)\nSTATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions | split(",") - $skip | join(","))"' versions.json >> "$GITHUB_ENV"
           echo "MINOR=$(cut -d. -f1-2 <<<"$VERSION")" >> "$GITHUB_ENV"
           case "$PKG" in
             php) build="$(jq -r .php.macos.build versions.json)" ;;
@@ -136,7 +138,9 @@ jobs:
           name: ${{ env.ASSET }}
       # Before Homebrew goes: jq is one of its tools.
       - name: Read versions.json
-        run: jq -r '.php.macos | "STATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions)"' versions.json >> "$GITHUB_ENV"
+        run: |
+          jq -r --arg pkg "$PKG" '(if $pkg == "frankenphp" then (.frankenphp.skip_extensions // "") | split(",") else [] end) as $skip
+            | .php.macos | "STATIC_EXTS=\(.static_extensions)\nSHARED_EXTS=\(.shared_extensions | split(",") - $skip | join(","))"' versions.json >> "$GITHUB_ENV"
       - name: Hide Homebrew
         run: sudo mv /opt/homebrew /opt/homebrew.hidden
       - name: Smoke test
diff --git a/README.md b/README.md
index 2cab50a..5218dc0 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,8 @@ its source).
 [php-windows-builder](https://github.com/php/php-windows-builder) against the official build of
 that minor, so they load into both `php` and `frankenphp` for Windows: apcu, igbinary, imagick
 (with ImageMagick), pcov, redis, xdebug and opentelemetry (from PHP 8.0 on, `min_php`), plus the
-MongoDB maintainers' own DLLs from PHP 8.1 on. Releases per extension, and per minor where one
+MongoDB maintainers' own DLLs from PHP 8.1 on and the PHP team's imap DLLs from PHP 8.4 on (see
+imap). Releases per extension, and per minor where one
 needs another release (xdebug 3.1 for PHP 7.4), are in `php.windows.extensions`. memcached is
 macOS only. On Windows, imagick reports its version
 as `@PACKAGE_VERSION@` (`phpversion('imagick')`), like the imagick maintainers' own Windows DLLs:
@@ -80,6 +81,20 @@ repository keeps the extension in `ext/`). It has no `composer.json` for php-win
 read its configure option from, so `--enable-opentelemetry` is passed explicitly. The smoke tests check that hooks fire
 (`scripts/smoke-opentelemetry.php`), not just that the extension loads.
 
+### imap
+
+imap left PHP's core in 8.4 for [PECL](https://pecl.php.net/package/imap). The macOS and Linux
+`php` packages have it as a shared extension, `ext/imap.so`, for every minor: 8.1–8.3 build the
+extension in php-src, 8.4 and newer the PECL release pinned in `packages/php/<platform>/build.sh`.
+Both link static-php-cli's build of the UW IMAP c-client with OpenSSL, without Kerberos (GSSAPI).
+The 8.4+ tarballs still ship `ext/imap/tests`, which static-php-cli takes for the extracted
+extension, so `build.sh` removes it first. `frankenphp` doesn't have imap: it isn't thread-safe,
+and `frankenphp.skip_extensions` leaves it out of the ZTS build.
+
+On Windows, the official builds have `php_imap.dll` up to PHP 8.3. For 8.4 and newer, the packs
+add the PHP team's own PECL DLL from downloads.php.net. Those come without a published checksum,
+so `php.windows.extensions.imap` pins the SHA-256 of each minor's zip.
+
 ### PostgreSQL extensions
 
 An extension (`pgvector`; PostGIS, pgRouting and TimescaleDB follow) is built for every
diff --git a/packages/php/linux/build.sh b/packages/php/linux/build.sh
index 8800e6c..c19d5a7 100644
--- a/packages/php/linux/build.sh
+++ b/packages/php/linux/build.sh
@@ -52,6 +52,8 @@ DOWNLOAD_ARGS="${DOWNLOAD_ARGS:-} --custom-url=xdebug:https://xdebug.org/files/x
 # opentelemetry (only its hook() is used, by Flock's runtime capture): static-php-cli takes
 # whatever PECL's newest is; pin it like xdebug. Shared and not loaded by default.
 DOWNLOAD_ARGS="$DOWNLOAD_ARGS --custom-url=opentelemetry:https://pecl.php.net/get/opentelemetry-1.4.2.tgz"
+# imap (PECL from PHP 8.4 on; 8.1–8.3 build the one in php-src): pinned like opentelemetry.
+DOWNLOAD_ARGS="$DOWNLOAD_ARGS --custom-url=ext-imap:https://pecl.php.net/get/imap-1.0.3.tgz"
 
 echo "::group::static-php-cli $SPC_VERSION"
 if [[ ! -x ./spc ]]; then
@@ -121,6 +123,13 @@ for attempt in 1 2 3 4; do
   # Start clean: libraries built for an extension we dropped would otherwise be linked
   # without their dependencies. Pre-built libraries unpack quickly.
   rm -rf buildroot source/php-src
+  # PHP 8.4+ tarballs still ship ext/imap/tests although imap moved to PECL: static-php-cli then
+  # takes ext/imap as extracted and skips the PECL source. Extract php-src first and drop the
+  # leftover (8.3 and older have the full extension, with config.m4, and keep it).
+  if [[ ",$all," == *",imap,"* ]]; then
+    ./spc extract php-src --source-only
+    [[ -f source/php-src/ext/imap/config.m4 ]] || rm -rf source/php-src/ext/imap
+  fi
   ok=1
   # static-php-cli's post-build sanity checks are stricter than we need; the smoke test verifies.
   ./spc build "$STATIC_EXTS" ${pending:+--build-shared="$pending"} "${build_flags[@]}" 2>&1 | tee spc-build.out || ok=0
diff --git a/packages/php/macos/build.sh b/packages/php/macos/build.sh
index 044fbd8..1cf3ec4 100644
--- a/packages/php/macos/build.sh
+++ b/packages/php/macos/build.sh
@@ -50,6 +50,8 @@ DOWNLOAD_ARGS="${DOWNLOAD_ARGS:-} --custom-url=xdebug:https://xdebug.org/files/x
 # opentelemetry (only its hook() is used, by Flock's runtime capture): static-php-cli takes
 # whatever PECL's newest is; pin it like xdebug. Shared and not loaded by default.
 DOWNLOAD_ARGS="$DOWNLOAD_ARGS --custom-url=opentelemetry:https://pecl.php.net/get/opentelemetry-1.4.2.tgz"
+# imap (PECL from PHP 8.4 on; 8.1–8.3 build the one in php-src): pinned like opentelemetry.
+DOWNLOAD_ARGS="$DOWNLOAD_ARGS --custom-url=ext-imap:https://pecl.php.net/get/imap-1.0.3.tgz"
 
 echo "::group::static-php-cli $SPC_VERSION"
 if [[ ! -x ./spc ]]; then
@@ -119,6 +121,13 @@ for attempt in 1 2 3 4; do
   # Start clean: libraries built for an extension we dropped would otherwise be linked
   # without their dependencies. Pre-built libraries unpack quickly.
   rm -rf buildroot source/php-src
+  # PHP 8.4+ tarballs still ship ext/imap/tests although imap moved to PECL: static-php-cli then
+  # takes ext/imap as extracted and skips the PECL source. Extract php-src first and drop the
+  # leftover (8.3 and older have the full extension, with config.m4, and keep it).
+  if [[ ",$all," == *",imap,"* ]]; then
+    ./spc extract php-src --source-only
+    [[ -f source/php-src/ext/imap/config.m4 ]] || rm -rf source/php-src/ext/imap
+  fi
   ok=1
   # static-php-cli's post-build sanity checks are stricter than we need; the smoke test verifies.
   ./spc build "$STATIC_EXTS" ${pending:+--build-shared="$pending"} "${build_flags[@]}" 2>&1 | tee spc-build.out || ok=0
diff --git a/scripts/windows/package-php-exts.ps1 b/scripts/windows/package-php-exts.ps1
index f328a4d..83f027b 100644
--- a/scripts/windows/package-php-exts.ps1
+++ b/scripts/windows/package-php-exts.ps1
@@ -4,6 +4,7 @@
 #   -Exts     the build jobs' artifacts, one directory ext-<name>-<minor> per extension
 #   -MongoDB  version of the MongoDB maintainers' own DLLs to add (PHP 8.1+), checked against
 #             GitHub's SHA-256 of the release asset
+# imap comes from php.windows.extensions.imap in versions.json (PHP 8.4+, the PHP team's PECL DLLs).
 # $env:EXTENSIONS lists the extensions built from source (JSON: name, repo, ref), as computed by the
 # workflow's config job from versions.json. Results go to stdout and $GITHUB_STEP_SUMMARY.
 # Usage: scripts/windows/package-php-exts.ps1 -Minor 8.4 -Exts exts -Out pkg [-MongoDB 2.5.5]
@@ -87,6 +88,22 @@ if ($MongoDB -and [version]$Minor -ge [version]'8.1') {
     $built['mongodb'] = $MongoDB
 }
 
+# imap: the official builds have it up to PHP 8.3; from 8.4 on it's PECL's, and the PHP team's own
+# DLLs come without a published checksum, so php.windows.extensions.imap pins their SHA-256.
+$imap = $versions.php.windows.extensions.imap
+$imapSum = $imap.sha256.$Minor
+if ($imapSum) {
+    $name = "php_imap-$($imap.version)-$Minor-ts-$vs-x64.zip"
+    $zip = Join-Path $work $name
+    Invoke-WebRequest "https://downloads.php.net/~windows/pecl/releases/imap/$($imap.version)/$name" -OutFile $zip
+    $sum = (Get-FileHash $zip -Algorithm SHA256).Hash.ToLower()
+    if ($sum -ne $imapSum) { throw "$name`: SHA-256 $sum, expected $imapSum" }
+    Expand-Archive $zip -DestinationPath (Join-Path $work 'imap')
+    Copy-Item (Join-Path $work 'imap/php_imap.dll') (Join-Path $extDir 'php_imap.dll')
+    Get-RepoLicense 'php/pecl-mail-imap' $imap.version 'imap'
+    $built['imap'] = $imap.version
+}
+
 # Load every DLL into the official build, as Flock will install it (ext\ and next to php.exe).
 Copy-Item (Join-Path $extDir '*') (Join-Path $php 'ext') -Force
 Get-ChildItem $Out -Filter *.dll | Copy-Item -Destination $php -Force
diff --git a/versions.json b/versions.json
index 9038a3b..d917d8b 100644
--- a/versions.json
+++ b/versions.json
@@ -2,24 +2,24 @@
   "php": {
     "macos": {
       "minors": ["8.1", "8.2", "8.3", "8.4", "8.5"],
-      "build": 2,
+      "build": 3,
       "spc": "2.8.5",
       "min_os": "13.0",
       "static_extensions": "bcmath,bz2,calendar,ctype,curl,dom,exif,fileinfo,filter,ftp,gd,gmp,iconv,igbinary,intl,ldap,mbregex,mbstring,mysqli,mysqlnd,opcache,openssl,pcntl,pdo,pdo_mysql,pdo_pgsql,pdo_sqlite,pgsql,phar,posix,readline,redis,session,shmop,simplexml,soap,sockets,sodium,sqlite3,sysvmsg,sysvsem,sysvshm,tokenizer,xml,xmlreader,xmlwriter,xsl,zip,zlib,apcu",
-      "shared_extensions": "xdebug,imagick,pcov,mongodb,memcached,opentelemetry"
+      "shared_extensions": "xdebug,imagick,pcov,mongodb,memcached,opentelemetry,imap"
     },
     "linux": {
       "minors": ["8.1", "8.2", "8.3", "8.4", "8.5"],
-      "build": 1,
+      "build": 2,
       "spc": "2.8.5",
       "static_extensions": "bcmath,bz2,calendar,ctype,curl,dom,exif,fileinfo,filter,ftp,gd,gmp,iconv,igbinary,intl,ldap,mbregex,mbstring,mysqli,mysqlnd,opcache,openssl,pcntl,pdo,pdo_mysql,pdo_pgsql,pdo_sqlite,pgsql,phar,posix,readline,redis,session,shmop,simplexml,soap,sockets,sodium,sqlite3,sysvmsg,sysvsem,sysvshm,tokenizer,xml,xmlreader,xmlwriter,xsl,zip,zlib,apcu",
-      "shared_extensions": "xdebug,imagick,pcov,mongodb,memcached,opentelemetry"
+      "shared_extensions": "xdebug,imagick,pcov,mongodb,memcached,opentelemetry,imap"
     },
     "windows": {
       "minors": ["7.4", "8.0", "8.1", "8.2", "8.3", "8.4", "8.5"],
       "build": 1,
       "extensions": {
-        "build": 2,
+        "build": 3,
         "from_source": {
           "apcu": { "repo": "krakjoe/apcu", "ref": "v5.1.28" },
           "igbinary": { "repo": "igbinary/igbinary", "ref": "3.2.16", "refs": { "8.5": "3.2.17RC1" }, "args": "--enable-igbinary=yes" },
@@ -29,13 +29,21 @@
           "xdebug": { "repo": "xdebug/xdebug", "ref": "3.5.3", "refs": { "7.4": "3.1.6", "8.6": "3.6.0alpha1" }, "args": "--with-xdebug=shared" },
           "opentelemetry": { "repo": "open-telemetry/opentelemetry-php-instrumentation", "url": "https://pecl.php.net/package/opentelemetry", "ref": "1.4.2", "min_php": "8.0", "args": "--enable-opentelemetry" }
         },
-        "mongodb": "2.5.5"
+        "mongodb": "2.5.5",
+        "imap": {
+          "version": "1.0.3",
+          "sha256": {
+            "8.4": "999b6041b0b6120a8b62da3e4011f3a79ee6731184e16f1b2c7cf4896b48367a",
+            "8.5": "fac1258ffab3425411770fdb0b1bfdd66f51eecbf22345aa259aec4ca873c342"
+          }
+        }
       }
     }
   },
   "frankenphp": {
     "version": "1.13.0",
     "minors": ["8.2", "8.3", "8.4", "8.5"],
+    "skip_extensions": "imap",
     "macos": { "build": 2 },
     "windows": { "build": 1 },
     "linux": { "build": 1 }