This is the IMAP extension extracted from the PHP source distribution. PHP versions after PHP 8.3 no longer bundle this extension.

This repository is a maintained fork of php/pecl-mail-imap, which describes itself as an archive. It keeps the same extension name, code and license.

Compared with the last PECL release (1.0.3), it adds:

• support for PHP 8.6 and php-src master
• installation with PIE
• automatic detection of the Kerberos and SSL support that c-client was built with, so a plain ./configure works with distribution packages
• a clear error from ./configure when c-client is not installed
• CI that runs the test suite against Dovecot on PHP 8.3 to 8.6, NTS and ZTS, and on Alpine Linux

The extension is still not safe to use from several threads in the same process (for example FrankenPHP). ZTS builds of PHP that run one thread per process, such as the CLI and PHP-FPM, work.

The documentation is still available as part of the PHP Documentation.

PIE builds the extension from source, so you need c-client (see below), a C compiler, autoconf and make, and unzip to unpack the download. On the official PHP Docker images the build tools are listed in $PHPIZE_DEPS. Then:

pie install sirlouen/imap

Windows is not supported through PIE yet.

Each release also comes with a package for pecl, which needs the same build tools as PIE except unzip. pecl cannot install it straight from the GitHub URL, so download it first:

curl -fLO https://github.com/SirLouen/pecl-mail-imap/releases/latest/download/imap.tgz
pecl install ./imap.tgz

Keep the ./: if imap.tgz is missing or broken, pecl install imap.tgz installs the old PECL imap 1.0.3 from pecl.php.net instead.

If pecl stops with "Extension 'imap' already loaded", remove your distribution's imap package first, for example apt remove php8.4-imap.

Then add extension=imap to your php.ini. On the official PHP Docker images, run docker-php-ext-enable imap instead.

In order for this extension to compile, you need to have the c-client installed. Debian 13, Ubuntu 26.10, Fedora and Homebrew no longer package it.

On Debian 12, Ubuntu 24.04 and Ubuntu 26.04 you can install it, plus unzip for PIE, with:

apt-get install libc-client-dev unzip

This also installs the Kerberos and SSL development libraries that this c-client is built with, and Kerberos and SSL support are enabled automatically.

Alpine's c-client is built with SSL support only:

apk add imap-dev openssl-dev