diff --git a/php-fpm/Dockerfile-56 b/php-fpm/Dockerfile-56
index 89cdb622..c0460462 100644
--- a/php-fpm/Dockerfile-56
+++ b/php-fpm/Dockerfile-56
@@ -329,6 +329,19 @@ RUN if [ ${INSTALL_IMAGEMAGICK} = true ]; then \
     docker-php-ext-enable imagick \
 ;fi
 
+#####################################
+# IMAP:
+#####################################
+ARG INSTALL_IMAP=false
+ENV INSTALL_IMAP ${INSTALL_IMAP}
+RUN if [ ${INSTALL_IMAP} = true ]; then \
+    apt-get update && \
+    apt-get install -y libc-client-dev libkrb5-dev && \
+    rm -r /var/lib/apt/lists/* && \
+    docker-php-ext-configure imap --with-kerberos --with-imap-ssl && \
+    docker-php-ext-install imap \
+;fi
+
 #
 #--------------------------------------------------------------------------
 # Final Touch