diff --git a/docs/alternative-architectures.md b/docs/alternative-architectures.md
index 07510d8a4..43c14b674 100644
--- a/docs/alternative-architectures.md
+++ b/docs/alternative-architectures.md
@@ -19,6 +19,6 @@ matrix_architecture: "arm32"
 This subsection is used for a reminder, how the different roles implement architecture differenes. This is **not** aimed at the users, so one does not have to do anything based on this subsection.
 
 On most roles [self-building](self-building.md) is used if the architecture is not `amd64`, however there are some special cases:
-- matrix-bridge-mautrix-facebook: there is built docker image for arm64 as well,
-- matrix-bridge-mautrix-hangouts: there is built docker image for arm64 as well,
-- matrix-nginx-proxy: Certbot has docker image for both arm32 and arm64, however tagging is used, which requires special handling.
+- `matrix-bridge-mautrix-facebook`: there is a pre-built Docker image for `arm64` as well
+- `matrix-bridge-mautrix-hangouts`: there is a pre-built Docker image for `arm64` as well
+- `matrix-nginx-proxy`: Certbot has a pre-built Docker image for both `arm32` and `arm64`, however tagging is used, which requires special handling.
diff --git a/docs/self-building.md b/docs/self-building.md
index 85d098120..e49120903 100644
--- a/docs/self-building.md
+++ b/docs/self-building.md
@@ -15,6 +15,7 @@ List of roles where self-building the Docker image is currently possible:
 - `matrix-riot-web`
 - `matrix-coturn`
 - `matrix-ma1sd`
+- `matrix-mailer`
 - `matrix-mautrix-facebook`
 - `matrix-mautrix-hangouts`
 - `matrix-mx-puppet-skype`
diff --git a/group_vars/matrix_servers b/group_vars/matrix_servers
index 8ff5ce96a..6835c93a3 100755
--- a/group_vars/matrix_servers
+++ b/group_vars/matrix_servers
@@ -537,11 +537,13 @@ matrix_jitsi_web_stun_servers: |
 #
 ######################################################################
 
-# By default, this playbook sets up a postfix mailer server (running in a container).
+# By default, this playbook sets up an exim mailer server (running in a container).
 # This is so that Synapse can send email reminders for unread messages.
 # Other services (like ma1sd), also use the mailer.
 matrix_mailer_enabled: true
 
+matrix_mailer_container_image_self_build: "{{ matrix_architecture != 'amd64'}}"
+
 ######################################################################
 #
 # /matrix-mailer
diff --git a/roles/matrix-mailer/defaults/main.yml b/roles/matrix-mailer/defaults/main.yml
index c1ffb0cf7..0a8fd13c0 100644
--- a/roles/matrix-mailer/defaults/main.yml
+++ b/roles/matrix-mailer/defaults/main.yml
@@ -2,6 +2,11 @@ matrix_mailer_enabled: true
 
 matrix_mailer_base_path: "{{ matrix_base_data_path }}/mailer"
 
+matrix_mailer_container_image_self_build: false
+matrix_mailer_container_image_self_build_repository_url: "https://github.com/devture/exim-relay"
+matrix_mailer_container_image_self_build_src_files_path: "{{ matrix_mailer_base_path }}/docker-src"
+matrix_mailer_container_image_self_build_version: "{{ matrix_mailer_docker_image.split(':')[1] }}"
+
 matrix_mailer_docker_image: "devture/exim-relay:4.93.1-r0"
 matrix_mailer_docker_image_force_pull: "{{ matrix_mailer_docker_image.endswith(':latest') }}"
 
diff --git a/roles/matrix-mailer/tasks/setup_mailer.yml b/roles/matrix-mailer/tasks/setup_mailer.yml
index 6104edfe6..99370638d 100644
--- a/roles/matrix-mailer/tasks/setup_mailer.yml
+++ b/roles/matrix-mailer/tasks/setup_mailer.yml
@@ -6,12 +6,15 @@
 
 - name: Ensure mailer base path exists
   file:
-    path: "{{ matrix_mailer_base_path }}"
+    path: "{{ item.path }}"
     state: directory
     mode: 0750
     owner: "{{ matrix_user_username }}"
     group: "{{ matrix_user_groupname }}"
-  when: matrix_mailer_enabled|bool
+  with_items:
+    - { path: "{{ matrix_mailer_base_path }}", when: true }
+    - { path: "{{ matrix_mailer_container_image_self_build_src_files_path }}", when: "{{ matrix_mailer_container_image_self_build }}" }
+  when: "matrix_mailer_enabled|bool and item.when"
 
 - name: Ensure mailer environment variables file created
   template:
@@ -20,13 +23,31 @@
     mode: 0640
   when: matrix_mailer_enabled|bool
 
-- name: Ensure mailer image is pulled
+- name: Ensure exim-relay repository is present on self-build
+  git:
+    repo: "{{ matrix_mailer_container_image_self_build_repository_url }}"
+    dest: "{{ matrix_mailer_container_image_self_build_src_files_path }}"
+    version: "{{ matrix_mailer_container_image_self_build_version }}"
+    force: "yes"
+  when: "matrix_mailer_container_image_self_build|bool"
+
+- name: Ensure exim-relay Docker image is built
+  docker_image:
+    name: "{{ matrix_mailer_docker_image }}"
+    source: build
+    build:
+      dockerfile: Dockerfile
+      path: "{{ matrix_mailer_container_image_self_build_src_files_path }}"
+      pull: yes
+  when: "matrix_mailer_enabled|bool and matrix_mailer_container_image_self_build|bool"
+
+- name: Ensure exim-relay image is pulled
   docker_image:
     name: "{{ matrix_mailer_docker_image }}"
     source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
     force_source: "{{ matrix_mailer_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
     force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mailer_docker_image_force_pull }}"
-  when: matrix_mailer_enabled|bool
+  when: "matrix_mailer_enabled|bool and not matrix_mailer_container_image_self_build|bool"
 
 - name: Ensure matrix-mailer.service installed
   template: