diff --git a/Providers/MMFCustomersGroupsServiceProvider.php b/Providers/MMFCustomersGroupsServiceProvider.php
index 93251ad..a1fc118 100644
--- a/Providers/MMFCustomersGroupsServiceProvider.php
+++ b/Providers/MMFCustomersGroupsServiceProvider.php
@@ -6,8 +6,13 @@
 
 namespace Modules\MMFCustomersGroups\Providers;
 
+use Eventy;
+use View;
+
 use Illuminate\Support\ServiceProvider;
 
+use Modules\MMFCustomersGroups\Entities\Mailbox;
+
 class MMFCustomersGroupsServiceProvider extends ServiceProvider {
 	/**
 	 * Indicates if loading of the provider is deferred.
@@ -75,8 +80,22 @@ class MMFCustomersGroupsServiceProvider extends ServiceProvider {
 	 */
 	public function hooks() {
 		// Add a menu entry to manage the customer groups.
-		\Eventy::addAction('menu.manage.after_mailboxes', function() {
-			echo \View::make('mmfcustomersgroups::partials/menu', [])->render();
+		Eventy::addAction('menu.manage.after_mailboxes', function() {
+			echo View::make('mmfcustomersgroups::partials/menu', [])->render();
 		});
+
+		// Add a list of customer groups to select from when writing a new conversation.
+		Eventy::addAction('conversation.create_form.before_subject', function($conversation, $mailbox, $thread) {
+			// We must fetch a fresh Mailbox instance,
+			// as the one that has been passed does not have a "groups" relationship.
+			$mailbox = Mailbox::find($mailbox->id);
+			$groups = $mailbox->groups;
+			echo View::make(
+				'mmfcustomersgroups::conversations/partials/groups-selection',
+				[
+					'groups' => $groups,
+				],
+			)->render();
+		}, 20, 3);
 	}
 }
diff --git a/Resources/views/conversations/partials/groups-selection.blade.php b/Resources/views/conversations/partials/groups-selection.blade.php
new file mode 100644
index 0000000..8ec33d2
--- /dev/null
+++ b/Resources/views/conversations/partials/groups-selection.blade.php
@@ -0,0 +1,36 @@
+<?php
+/*
+ SPDX-License-Identifier: AGPL-3.0-only
+ SPDX-FileCopyrightText: © 2024 Millions Missing FRANCE <info@millionsmissing.fr>
+ */
+?>
+
+@include('partials/flash_messages')
+
+<!-- List of Customers Groups that should be included in this Conversation -->
+<div class="form-group{{ $errors->has('groups') ? ' has-error' : '' }}">
+	<label for="groups" class="col-sm-2 control-label">{{ __('Groups selection') }}</label>
+	<div class="col-sm-9">
+		<div class="multi-container">
+			@foreach ( $groups as $group )
+				<div class="control-group">
+					<div class="controls">
+						<label
+							class="control-label checkbox"
+							for="group-{{ $group->id }}"
+							style="text-align: left;"
+						>
+							<input
+								type="checkbox"
+								name="groups[]"
+								id="group-{{ $group->id }}"
+								value="{{ $group->id }}"
+							>
+							{{ $group->name }}
+						</label>
+					</div>
+				</div>
+			@endforeach
+		</div>
+	</div>
+</div>