diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b584ca8..82d2527 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,7 +4,7 @@ services:
 variables:
   DOCKER_AUTH_CONFIG: ${_DOCKER_AUTH_CONFIG}
   PLATFORM: "linux/amd64"
-  ARM_BUILDS: ",chromium,firefox,gimp,rdesktop,remmina,terminal,ubuntu-bionic-desktop,ubuntu-focal-desktop,vlc,vs-code,doom,sublime-text,tor-browser,java-dev,telegram,opensuse-15-desktop,oracle-8-desktop,libre-office,"
+  ARM_BUILDS: ",chromium,firefox,gimp,rdesktop,remmina,terminal,ubuntu-bionic-desktop,ubuntu-focal-desktop,vlc,vs-code,doom,sublime-text,tor-browser,java-dev,telegram,opensuse-15-desktop,oracle-8-desktop,libre-office,thunderbird,"
   CORE_IMAGE_TAG: "develop"
   CORE_IMAGE: "core-ubuntu-focal"
   USE_PRIVATE_IMAGES: 0
@@ -24,6 +24,7 @@ variables:
   - sublime-text
   - telegram
   - terminal
+  - thunderbird
   - tor-browser
   - ubuntu-focal-desktop
   - vlc
@@ -57,8 +58,8 @@ variables:
 
 stages:
   - build
-  - manifest
   - test
+  - manifest
   - readme
 
 before_script:
@@ -123,7 +124,7 @@ build_app_images:
     - aws-autoscale
   parallel:
     matrix:
-      - KASM_IMAGE: [doom, sublime-text, gimp, vs-code, slack, teams, only-office, zoom, signal, steam, postman, insomnia, zsnes, vlc, maltego, telegram, hunchly, java-dev, terminal, vmware-horizon, remmina, rdesktop, discord, libre-office]
+      - KASM_IMAGE: [doom, sublime-text, gimp, vs-code, slack, teams, only-office, zoom, signal, steam, postman, insomnia, zsnes, vlc, maltego, telegram, hunchly, java-dev, terminal, vmware-horizon, remmina, rdesktop, discord, libre-office, thunderbird]
 
 build_ubuntu_desktop_images:
   stage: build
@@ -189,10 +190,7 @@ build_non_ubuntu:
     matrix:
       - KASM_IMAGE: [centos-7-desktop, tracelabs, opensuse-15-desktop, oracle-7-desktop, oracle-8-desktop]
 
-
-
 # These jobs should run on the feature/bugfix branches - anything that is not the develop or release branches. It should only push images to the private repos
-
 build_multi_arch_dev:
   stage: build
   image: ${ORG_NAME}/docker-buildx-private:develop
@@ -391,7 +389,7 @@ build_schedules_app_images:
     - aws-autoscale
   parallel:
     matrix:
-      - KASM_IMAGE: [doom, sublime-text, gimp, vs-code, slack, teams, only-office, zoom, signal, steam, postman, insomnia, zsnes, vlc, maltego, telegram, hunchly, java-dev, terminal, vmware-horizon, remmina, rdesktop, discord, libre-office]
+      - KASM_IMAGE: [doom, sublime-text, gimp, vs-code, slack, teams, only-office, zoom, signal, steam, postman, insomnia, zsnes, vlc, maltego, telegram, hunchly, java-dev, terminal, vmware-horizon, remmina, rdesktop, discord, libre-office, thunderbird]
         CORE_IMAGE: [core-ubuntu-bionic, core-ubuntu-focal]
 
 build_schedules_ubuntu_desktop_images:
@@ -519,6 +517,7 @@ update_readmes:
           - teams
           - telegram
           - terminal
+          - thunderbird
           - tor-browser
           - tracelabs
           - ubuntu-focal-desktop
diff --git a/dockerfile-kasm-centos-7-desktop b/dockerfile-kasm-centos-7-desktop
index 65643bf..f97ed9b 100644
--- a/dockerfile-kasm-centos-7-desktop
+++ b/dockerfile-kasm-centos-7-desktop
@@ -25,6 +25,9 @@ COPY ./src/ubuntu/install/firefox/ $INST_SCRIPTS/firefox/
 COPY ./src/ubuntu/install/firefox/firefox.desktop $HOME/Desktop/
 RUN bash $INST_SCRIPTS/firefox/install_firefox.sh && rm -rf $INST_SCRIPTS/firefox/
 
+# Install Thunderbird
+COPY ./src/ubuntu/install/thunderbird $INST_SCRIPTS/thunderbird/
+RUN bash $INST_SCRIPTS/thunderbird/install_thunderbird.sh  && rm -rf $INST_SCRIPTS/thunderbird/
 
 ######### End Customizations ###########
 
diff --git a/dockerfile-kasm-opensuse-15-desktop b/dockerfile-kasm-opensuse-15-desktop
index 71f81df..f52a988 100644
--- a/dockerfile-kasm-opensuse-15-desktop
+++ b/dockerfile-kasm-opensuse-15-desktop
@@ -80,6 +80,10 @@ RUN bash $INST_SCRIPTS/terraform/install_terraform.sh  && rm -rf $INST_SCRIPTS/t
 COPY ./src/opensuse/install/telegram $INST_SCRIPTS/telegram/
 RUN bash $INST_SCRIPTS/telegram/install_telegram.sh  && rm -rf $INST_SCRIPTS/telegram/
 
+### Install Thunderbird
+COPY ./src/ubuntu/install/thunderbird $INST_SCRIPTS/thunderbird/
+RUN bash $INST_SCRIPTS/thunderbird/install_thunderbird.sh  && rm -rf $INST_SCRIPTS/thunderbird/
+
 #ADD ./src/common/scripts $STARTUPDIR
 RUN $STARTUPDIR/set_user_permission.sh $HOME
 
diff --git a/dockerfile-kasm-oracle-7-desktop b/dockerfile-kasm-oracle-7-desktop
index 0c1e6a6..21b89f9 100644
--- a/dockerfile-kasm-oracle-7-desktop
+++ b/dockerfile-kasm-oracle-7-desktop
@@ -76,6 +76,10 @@ RUN bash $INST_SCRIPTS/terraform/install_terraform.sh  && rm -rf $INST_SCRIPTS/t
 COPY ./src/oracle/install/telegram $INST_SCRIPTS/telegram/
 RUN bash $INST_SCRIPTS/telegram/install_telegram.sh  && rm -rf $INST_SCRIPTS/telegram/
 
+### Install Thunderbird
+COPY ./src/ubuntu/install/thunderbird $INST_SCRIPTS/thunderbird/
+RUN bash $INST_SCRIPTS/thunderbird/install_thunderbird.sh  && rm -rf $INST_SCRIPTS/thunderbird/
+
 #ADD ./src/common/scripts $STARTUPDIR
 RUN $STARTUPDIR/set_user_permission.sh $HOME
 
diff --git a/dockerfile-kasm-oracle-8-desktop b/dockerfile-kasm-oracle-8-desktop
index c5d20a9..5f75e93 100644
--- a/dockerfile-kasm-oracle-8-desktop
+++ b/dockerfile-kasm-oracle-8-desktop
@@ -88,6 +88,10 @@ RUN bash $INST_SCRIPTS/terraform/install_terraform.sh  && rm -rf $INST_SCRIPTS/t
 COPY ./src/oracle/install/telegram $INST_SCRIPTS/telegram/
 RUN bash $INST_SCRIPTS/telegram/install_telegram.sh  && rm -rf $INST_SCRIPTS/telegram/
 
+### Install Thunderbird
+COPY ./src/ubuntu/install/thunderbird $INST_SCRIPTS/thunderbird/
+RUN bash $INST_SCRIPTS/thunderbird/install_thunderbird.sh  && rm -rf $INST_SCRIPTS/thunderbird/
+
 #ADD ./src/common/scripts $STARTUPDIR
 RUN $STARTUPDIR/set_user_permission.sh $HOME
 
diff --git a/dockerfile-kasm-thunderbird b/dockerfile-kasm-thunderbird
new file mode 100644
index 0000000..cdc1974
--- /dev/null
+++ b/dockerfile-kasm-thunderbird
@@ -0,0 +1,35 @@
+ARG BASE_TAG="develop"
+ARG BASE_IMAGE="core-ubuntu-focal"
+FROM kasmweb/$BASE_IMAGE:$BASE_TAG
+USER root
+
+ENV HOME /home/kasm-default-profile
+ENV STARTUPDIR /dockerstartup
+ENV INST_SCRIPTS $STARTUPDIR/install
+WORKDIR $HOME
+
+######### Customize Container Here ###########
+
+
+COPY ./src/ubuntu/install/thunderbird $INST_SCRIPTS/thunderbird/
+RUN bash $INST_SCRIPTS/thunderbird/install_thunderbird.sh  && rm -rf $INST_SCRIPTS/thunderbird/
+
+COPY ./src/ubuntu/install/thunderbird/custom_startup.sh $STARTUPDIR/custom_startup.sh
+RUN chmod +x $STARTUPDIR/custom_startup.sh
+RUN chmod 755 $STARTUPDIR/custom_startup.sh
+
+
+# Update the desktop environment to be optimized for a single application
+RUN cp $HOME/.config/xfce4/xfconf/single-application-xfce-perchannel-xml/* $HOME/.config/xfce4/xfconf/xfce-perchannel-xml/
+RUN cp /usr/share/extra/backgrounds/bg_kasm.png /usr/share/extra/backgrounds/bg_default.png
+RUN apt-get remove -y xfce4-panel
+
+######### End Customizations ###########
+
+RUN chown 1000:0 $HOME
+
+ENV HOME /home/kasm-user
+WORKDIR $HOME
+RUN mkdir -p $HOME && chown -R 1000:0 $HOME
+
+USER 1000
diff --git a/dockerfile-kasm-ubuntu-focal-desktop b/dockerfile-kasm-ubuntu-focal-desktop
index 3cfa1ff..20b0cce 100644
--- a/dockerfile-kasm-ubuntu-focal-desktop
+++ b/dockerfile-kasm-ubuntu-focal-desktop
@@ -91,6 +91,10 @@ RUN bash $INST_SCRIPTS/terraform/install_terraform.sh  && rm -rf $INST_SCRIPTS/t
 COPY ./src/ubuntu/install/telegram $INST_SCRIPTS/telegram/
 RUN bash $INST_SCRIPTS/telegram/install_telegram.sh  && rm -rf $INST_SCRIPTS/telegram/
 
+### Install Thunderbird
+COPY ./src/ubuntu/install/thunderbird $INST_SCRIPTS/thunderbird/
+RUN bash $INST_SCRIPTS/thunderbird/install_thunderbird.sh  && rm -rf $INST_SCRIPTS/thunderbird/
+
 #ADD ./src/common/scripts $STARTUPDIR
 RUN $STARTUPDIR/set_user_permission.sh $HOME
 
diff --git a/docs/thunderbird/README.md b/docs/thunderbird/README.md
new file mode 100644
index 0000000..3720563
--- /dev/null
+++ b/docs/thunderbird/README.md
@@ -0,0 +1,7 @@
+# About This Image
+
+This Image contains a browser-accessible version of [Thunderbird](https://www.thunderbird.net/).
+
+![Screenshot][Image_Screenshot]
+
+[Image_Screenshot]: https://5856039.fs1.hubspotusercontent-na1.net/hubfs/5856039/dockerhub/image-screenshots/thunderbird.png "Image Screenshot"
diff --git a/docs/thunderbird/description.txt b/docs/thunderbird/description.txt
new file mode 100644
index 0000000..960d683
--- /dev/null
+++ b/docs/thunderbird/description.txt
@@ -0,0 +1 @@
+Thunderbird for Kasm Workspaces
diff --git a/src/ubuntu/install/thunderbird/custom_startup.sh b/src/ubuntu/install/thunderbird/custom_startup.sh
new file mode 100644
index 0000000..8f8391c
--- /dev/null
+++ b/src/ubuntu/install/thunderbird/custom_startup.sh
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+set -ex
+START_COMMAND="thunderbird"
+PGREP="thunderbird"
+export MAXIMIZE="true"
+export MAXIMIZE_NAME="Mozilla"
+MAXIMIZE_SCRIPT=$STARTUPDIR/maximize_window.sh
+DEFAULT_ARGS=""
+ARGS=${APP_ARGS:-$DEFAULT_ARGS}
+
+options=$(getopt -o gau: -l go,assign,url: -n "$0" -- "$@") || exit
+eval set -- "$options"
+
+while [[ $1 != -- ]]; do
+    case $1 in
+        -g|--go) GO='true'; shift 1;;
+        -a|--assign) ASSIGN='true'; shift 1;;
+        -u|--url) OPT_URL=$2; shift 2;;
+        *) echo "bad option: $1" >&2; exit 1;;
+    esac
+done
+shift
+
+# Process non-option arguments.
+for arg; do
+    echo "arg! $arg"
+done
+
+FORCE=$2
+
+kasm_exec() {
+    if [ -n "$OPT_URL" ] ; then
+        URL=$OPT_URL
+    elif [ -n "$1" ] ; then
+        URL=$1
+    fi 
+    
+    # Since we are execing into a container that already has the browser running from startup, 
+    #  when we don't have a URL to open we want to do nothing. Otherwise a second browser instance would open. 
+    if [ -n "$URL" ] ; then
+        /usr/bin/filter_ready
+        /usr/bin/desktop_ready
+        bash ${MAXIMIZE_SCRIPT} &
+        $START_COMMAND $ARGS $OPT_URL
+    else
+        echo "No URL specified for exec command. Doing nothing."
+    fi
+}
+
+kasm_startup() {
+    if [ -n "$KASM_URL" ] ; then
+        URL=$KASM_URL
+    elif [ -z "$URL" ] ; then
+        URL=$LAUNCH_URL
+    fi
+
+    if [ -z "$DISABLE_CUSTOM_STARTUP" ] ||  [ -n "$FORCE" ] ; then
+        
+        while true
+        do
+            if ! pgrep -x $PGREP > /dev/null
+            then
+                /usr/bin/filter_ready
+                /usr/bin/desktop_ready
+                set +e
+                bash ${MAXIMIZE_SCRIPT} &
+                $START_COMMAND $ARGS $URL
+                set -e
+            fi
+            sleep 1
+        done
+    
+    fi
+
+} 
+
+if [ -n "$GO" ] || [ -n "$ASSIGN" ] ; then
+    kasm_exec
+else
+    kasm_startup
+fi
diff --git a/src/ubuntu/install/thunderbird/install_thunderbird.sh b/src/ubuntu/install/thunderbird/install_thunderbird.sh
new file mode 100644
index 0000000..4a6f2cf
--- /dev/null
+++ b/src/ubuntu/install/thunderbird/install_thunderbird.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -ex
+
+# Install
+if [[ "${DISTRO}" == @(centos|oracle7|oracle8) ]]; then
+  if [ "${DISTRO}" == "oracle8" ]; then
+    dnf install -y thunderbird
+    dnf clean all
+  else
+    yum install -y thunderbird
+    yum clean all
+  fi
+elif [ "${DISTRO}" == "opensuse" ]; then
+  zypper install -yn MozillaThunderbird
+  zypper clean --all
+else
+  apt-get update
+  apt-get install -y thunderbird
+  rm -rf \
+    /var/lib/apt/lists/* \
+    /var/tmp/*
+fi
+
+# Desktop icon
+cp /usr/share/applications/thunderbird.desktop $HOME/Desktop/
+chmod +x $HOME/Desktop/thunderbird.desktop