nextcloud · dtretyakov · Apr 13, 2026 · Apr 14, 2026
diff --git a/CHANGELOG.en.md b/CHANGELOG.en.md
@@ -5,6 +5,18 @@
 
 # Changelog
 
+## Unreleased
+
+- **Confirmation emails for respondents**
+
+    Form owners can enable an automatic confirmation email that is sent to the respondent after a successful submission.
+    Requires an email-validated short text question in the form.
+
+    Supported placeholders in subject/body:
+
+    - `{formTitle}`, `{formDescription}`
+    - `{<fieldName>}` (question `name` or text, sanitized)
+
 ## v5.2.0 - 2025-09-25
 
 - **Time: restrictions and ranges**

diff --git a/docs/API_v3.md b/docs/API_v3.md
@@ -175,6 +175,9 @@ Returns the full-depth object of the requested form (without submissions).
   "state": 0,
   "lockedBy": null,
   "lockedUntil": null,
+  "confirmationEmailEnabled": false,
+  "confirmationEmailSubject": null,
+  "confirmationEmailBody": null,
   "permissions": [
     "edit",
     "results",

diff --git a/docs/DataStructure.md b/docs/DataStructure.md
@@ -21,6 +21,9 @@ This document describes the Object-Structure, that is used within the Forms App
 | description          | String                               | max. 8192 ch.                           | The Form description                                                                                                             |
 | ownerId              | String                               |                                         | The nextcloud userId of the form owner                                                                                           |
 | submissionMessage    | String                               | max. 2048 ch.                           | Optional custom message, with Markdown support, to be shown to users when the form is submitted (default is used if set to null) |
+| confirmationEmailEnabled | Boolean                          |                                         | If enabled, send a confirmation email to the respondent after submission                                                         |
+| confirmationEmailSubject | String                           | max. 255 ch.                            | Optional confirmation email subject template (supports placeholders)                                                              |
+| confirmationEmailBody    | String                           |                                         | Optional confirmation email body template (plain text, supports placeholders)                                                    |
 | created              | unix timestamp                       |                                         | When the form has been created                                                                                                   |
 | access               | [Access-Object](#access-object)      |                                         | Describing access-settings of the form                                                                                           |
 | expires              | unix-timestamp                       |                                         | When the form should expire. Timestamp `0` indicates _never_                                                                     |
@@ -46,6 +49,9 @@ This document describes the Object-Structure, that is used within the Forms App
   "title": "Form 1",
   "description": "Description Text",
   "ownerId": "jonas",
+  "confirmationEmailEnabled": false,
+  "confirmationEmailSubject": null,
+  "confirmationEmailBody": null,
   "created": 1611240961,
   "access": {},
   "expires": 0,

diff --git a/lib/Constants.php b/lib/Constants.php
@@ -147,6 +147,7 @@ class Constants {
 	];
 
 	public const EXTRA_SETTINGS_SHORT = [
+		'confirmationEmailRecipient' => ['boolean'],
 		'validationType' => ['string'],
 		'validationRegex' => ['string'],
 	];

diff --git a/lib/Db/Form.php b/lib/Db/Form.php
@@ -53,6 +53,14 @@
  * @method int|null getMaxSubmissions()
  * @method void setMaxSubmissions(int|null $value)
  * @method void setLockedUntil(int|null $value)
+ * @method int getConfirmationEmailEnabled()
+ * @method void setConfirmationEmailEnabled(bool $value)
+ * @method string|null getConfirmationEmailSubject()
+ * @method void setConfirmationEmailSubject(string|null $value)
+ * @method string|null getConfirmationEmailBody()
+ * @method void setConfirmationEmailBody(string|null $value)
+ * @method int|null getConfirmationEmailRecipient()
+ * @method void setConfirmationEmailRecipient(int|null $value)
  */
 class Form extends Entity {
 	protected $hash;
@@ -74,6 +82,10 @@ class Form extends Entity {
 	protected $lockedBy;
 	protected $lockedUntil;
 	protected $maxSubmissions;
+	protected $confirmationEmailEnabled;
+	protected $confirmationEmailSubject;
+	protected $confirmationEmailBody;
+	protected $confirmationEmailRecipient;
 
 	/**
 	 * Form constructor.
@@ -90,6 +102,8 @@ public function __construct() {
 		$this->addType('lockedBy', 'string');
 		$this->addType('lockedUntil', 'integer');
 		$this->addType('maxSubmissions', 'integer');
+		$this->addType('confirmationEmailEnabled', 'boolean');
+		$this->addType('confirmationEmailRecipient', 'integer');
 	}
 
 	// JSON-Decoding of access-column.
@@ -164,6 +178,10 @@ public function setAccess(array $access): void {
 	 *   lockedBy: ?string,
 	 *   lockedUntil: ?int,
 	 *   maxSubmissions: ?int,
+	 *   confirmationEmailEnabled: bool,
+	 *   confirmationEmailSubject: ?string,
+	 *   confirmationEmailBody: ?string,
+	 *   confirmationEmailRecipient: ?int,
 	 *  }
 	 */
 	public function read() {
@@ -188,6 +206,10 @@ public function read() {
 			'lockedBy' => $this->getLockedBy(),
 			'lockedUntil' => $this->getLockedUntil(),
 			'maxSubmissions' => $this->getMaxSubmissions(),
+			'confirmationEmailEnabled' => (bool)$this->getConfirmationEmailEnabled(),
+			'confirmationEmailSubject' => $this->getConfirmationEmailSubject(),
+			'confirmationEmailBody' => $this->getConfirmationEmailBody(),
+			'confirmationEmailRecipient' => $this->getConfirmationEmailRecipient(),
 		];
 	}
 }
diff --git a/lib/Migration/Version050301Date20260413233000.php b/lib/Migration/Version050301Date20260413233000.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Forms\Migration;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+/**
+ * Add confirmation email fields to forms
+ */
+class Version050301Date20260413233000 extends SimpleMigrationStep {
+
+	/**
+	 * @param IOutput $output
+	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+	 * @param array $options
+	 * @return null|ISchemaWrapper
+	 */
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+		$table = $schema->getTable('forms_v2_forms');
+
+		if (!$table->hasColumn('confirmation_email_enabled')) {
+			$table->addColumn('confirmation_email_enabled', Types::BOOLEAN, [
+				'notnull' => false,
+				'default' => 0,
+			]);
+		}
+
+		if (!$table->hasColumn('confirmation_email_subject')) {
+			$table->addColumn('confirmation_email_subject', Types::STRING, [
+				'notnull' => false,
+				'default' => null,
+				'length' => 255,
+			]);
+		}
+
+		if (!$table->hasColumn('confirmation_email_body')) {
+			$table->addColumn('confirmation_email_body', Types::TEXT, [
+				'notnull' => false,
+				'default' => null,
+			]);
+		}
+
+		if (!$table->hasColumn('confirmation_email_recipient')) {
+			$table->addColumn('confirmation_email_recipient', Types::INTEGER, [
+				'notnull' => false,
+				'default' => null,
+			]);
+		}
+
+		return $schema;
+	}
+}
diff --git a/lib/ResponseDefinitions.php b/lib/ResponseDefinitions.php
@@ -26,6 +26,7 @@
  *   dateMax?: int,
  *   dateMin?: int,
  *   dateRange?: bool,
+ *   confirmationEmailRecipient?: bool,
  *   maxAllowedFilesCount?: int,
  *   maxFileSize?: int,
  *   optionsHighest?: 2|3|4|5|6|7|8|9|10,
@@ -141,8 +142,11 @@
  *   shares: list<FormsShare>,
  *   submissionCount?: int,
  *   submissionMessage: ?string,
- * }
- *
+ *   confirmationEmailEnabled: bool,
+ *   confirmationEmailSubject: ?string,
+ *   confirmationEmailBody: ?string,
+ *   confirmationEmailRecipient: ?int,
+ * } *
  * @psalm-type FormsUploadedFile = array{
  *   uploadedFileId: int,
  *   fileName: string

diff --git a/lib/Service/FormsService.php b/lib/Service/FormsService.php
@@ -9,6 +9,7 @@
 
 use OCA\Forms\Activity\ActivityManager;
 use OCA\Forms\Constants;
+use OCA\Forms\Db\AnswerMapper;
 use OCA\Forms\Db\Form;
 use OCA\Forms\Db\FormMapper;
 use OCA\Forms\Db\OptionMapper;
@@ -34,6 +35,8 @@
 use OCP\IUser;
 use OCP\IUserManager;
 use OCP\IUserSession;
+use OCP\Mail\IEmailValidator;
+use OCP\Mail\IMailer;
 use OCP\Search\ISearchQuery;
 use OCP\Security\ISecureRandom;
 use OCP\Share\IShare;
@@ -67,6 +70,9 @@ public function __construct(
 		private IL10N $l10n,
 		private LoggerInterface $logger,
 		private IEventDispatcher $eventDispatcher,
+		private IMailer $mailer,
+		private IEmailValidator $emailValidator,
+		private AnswerMapper $answerMapper,
 	) {
 		$this->currentUser = $userSession->getUser();
 	}
@@ -739,6 +745,170 @@ public function notifyNewSubmission(Form $form, Submission $submission): void {
 		}
 
 		$this->eventDispatcher->dispatchTyped(new FormSubmittedEvent($form, $submission));
+
+		// Send confirmation email if enabled
+		$this->sendConfirmationEmail($form, $submission);
+	}
+
+	/**
+	 * Send confirmation email to the respondent
+	 *
+	 * @param Form $form The form that was submitted
+	 * @param Submission $submission The submission
+	 */
+	private function sendConfirmationEmail(Form $form, Submission $submission): void {
+		// Check if confirmation email is enabled
+		if (!$form->getConfirmationEmailEnabled()) {
+			return;
+		}
+
+		$subject = $form->getConfirmationEmailSubject();
+		$body = $form->getConfirmationEmailBody();
+
+		// If no subject or body is set, use defaults
+		if (empty($subject)) {
+			$subject = $this->l10n->t('Thank you for your submission');
+		}
+		if (empty($body)) {
+			$body = $this->l10n->t('Thank you for submitting the form "%s".', [$form->getTitle()]);
+		}
+
+		// Get questions and answers
+		$questions = $this->getQuestions($form->getId());
+		$answers = $this->answerMapper->findBySubmission($submission->getId());
+
+		$answerMap = [];
+		foreach ($answers as $answer) {
+			$questionId = $answer->getQuestionId();
+			if (!isset($answerMap[$questionId])) {
+				$answerMap[$questionId] = [];
+			}
+			$answerMap[$questionId][] = $answer->getText();
+		}
+
+		$recipientQuestion = $this->getConfirmationEmailRecipientQuestion($questions);
+		if ($recipientQuestion === null) {
+			$this->logger->debug('No confirmation email recipient question is available', [
+				'formId' => $form->getId(),
+				'submissionId' => $submission->getId(),
+			]);
+			return;
+		}
+
+		$recipientQuestionId = $recipientQuestion['id'];
+		$recipientEmail = $answerMap[$recipientQuestionId][0] ?? null;
+		if ($recipientEmail === null || !$this->emailValidator->isValid($recipientEmail)) {
+			$this->logger->debug('No valid email address found in submission for confirmation email', [
+				'formId' => $form->getId(),
+				'submissionId' => $submission->getId(),
+			]);
+			return;
+		}
+
+		// Replace placeholders in subject and body
+		$replacements = [
+			'{formTitle}' => $form->getTitle(),
+			'{formDescription}' => $form->getDescription() ?? '',
+		];
+
+		// Add field placeholders (e.g., {name}, {email})
+		foreach ($questions as $question) {
+			$questionId = $question['id'];
+			$questionName = $question['name'] ?? '';
+			$questionText = $question['text'] ?? '';
+
+			// Use question name if available, otherwise use text
+			$fieldKey = !empty($questionName) ? $questionName : $questionText;
+			// Sanitize field key for placeholder (remove special chars, lowercase)
+			$fieldKey = strtolower(preg_replace('/[^a-zA-Z0-9]/', '', $fieldKey));
+
+			if (!empty($answerMap[$questionId])) {
+				$answerValue = implode('; ', $answerMap[$questionId]);
+				$replacements['{' . $fieldKey . '}'] = $answerValue;
+				// Also support {questionName} format
+				if (!empty($questionName)) {
+					$replacements['{' . strtolower(preg_replace('/[^a-zA-Z0-9]/', '', $questionName)) . '}'] = $answerValue;
+				}
+			}
+		}
+
+		// Apply replacements
+		$subject = str_replace(array_keys($replacements), array_values($replacements), $subject);
+		$body = str_replace(array_keys($replacements), array_values($replacements), $body);
+
+		try {
+			$message = $this->mailer->createMessage();
+			$message->setSubject($subject);
+			$message->setPlainBody($body);
+			$message->setTo([$recipientEmail]);
+
+			$this->mailer->send($message);
+			$this->logger->debug('Confirmation email sent successfully', [
+				'formId' => $form->getId(),
+				'submissionId' => $submission->getId(),
+				'recipient' => $recipientEmail,
+			]);
+		} catch (\Exception $e) {
+			// Handle exceptions silently, as this is not critical.
+			// We don't want to break the submission process just because of an email error.
+			$this->logger->error(
+				'Error while sending confirmation email',
+				[
+					'exception' => $e,
+					'formId' => $form->getId(),
+					'submissionId' => $submission->getId(),
+				]
+			);
+		}
+	}
+
+	/**
+	 * @param list<FormsQuestion> $questions
+	 * @return FormsQuestion|null
+	 */
+	private function getConfirmationEmailRecipientQuestion(array $questions): ?array {
+		$emailQuestions = array_values(array_filter(
+			$questions,
+			fn (array $question): bool => $this->isConfirmationEmailQuestion($question),
+		));
+
+		if ($emailQuestions === []) {
+			return null;
+		}
+
+		$explicitRecipients = array_values(array_filter(
+			$emailQuestions,
+			function (array $question): bool {
+				$extraSettings = (array)($question['extraSettings'] ?? []);
+				return !empty($extraSettings['confirmationEmailRecipient']);
+			},
+		));
+
+		if (count($explicitRecipients) === 1) {
+			return $explicitRecipients[0];
+		}
+
+		if (count($explicitRecipients) > 1) {
+			return null;
+		}
+
+		if (count($emailQuestions) === 1) {
+			return $emailQuestions[0];
+		}
+
+		return null;
+	}
+
+	/**
+	 * @param FormsQuestion $question
+	 */
+	private function isConfirmationEmailQuestion(array $question): bool {
+		if (($question['type'] ?? null) !== Constants::ANSWER_TYPE_SHORT) {
+			return false;
+		}
+
+		$extraSettings = (array)($question['extraSettings'] ?? []);
+		return ($extraSettings['validationType'] ?? null) === 'email';
 	}
 
 	/**