diff --git a/e2e/README.md b/e2e/README.md
index 9bab60d8c..eade37a54 100644
--- a/e2e/README.md
+++ b/e2e/README.md
@@ -70,7 +70,7 @@ The file should be located in the `/e2e` directory.
 Example `.env` file:
 ```
 # =======================
-# ENVIRONEMNT VARIABLES
+# ENVIRONMENT VARIABLES
 #
 # Copy this file to create a .env file and make necessary changes.
 # NOTE! Copy the relevant values from local.settings.php to these environment variables.
diff --git a/e2e/utils/helpers.ts b/e2e/utils/helpers.ts
index 7391b401c..be4c2c24d 100644
--- a/e2e/utils/helpers.ts
+++ b/e2e/utils/helpers.ts
@@ -156,6 +156,22 @@ const waitForTextWithInterval = async (
   }
 }
 
+/**
+ * The getFulfilledResponse function.
+ *
+ * Wait for a fulfilled response from a request.
+ *
+ * @param page
+ *  Playwright page object
+ */
+async function getFulfilledResponse(page: Page) {
+  const response = await page.waitForResponse(async (response) => {
+    return response.ok();
+  });
+
+  return response.json();
+}
+
 /**
  * The logCurrentUrl function.
  *
@@ -169,11 +185,12 @@ const logCurrentUrl = async (page: Page) => {
 }
 
 export {
-  slowLocator,
   extractPath,
-  hideSlidePopup,
   getApplicationNumberFromBreadCrumb,
-  waitForTextWithInterval,
+  getFulfilledResponse,
+  hideSlidePopup,
   logCurrentUrl,
+  slowLocator,
+  waitForTextWithInterval,
 };
 
diff --git a/e2e/utils/validation_helpers.ts b/e2e/utils/validation_helpers.ts
index 30678fde7..0af9c7727 100644
--- a/e2e/utils/validation_helpers.ts
+++ b/e2e/utils/validation_helpers.ts
@@ -3,7 +3,9 @@ import {logger} from "./logger";
 import {FormField, FormData, FormFieldWithRemove} from "./data/test_data"
 import {viewPageBuildSelectorForItem} from "./view_page_helpers";
 import {PROFILE_INPUT_DATA, ProfileInputData} from "./data/profile_input_data";
-import {logCurrentUrl} from "./helpers";
+import {getFulfilledResponse, logCurrentUrl} from "./helpers";
+import { uploadFile } from './input_helpers';
+import { ATTACHMENTS } from './data/attachment_data';
 
 /**
  *  The pageType type.
@@ -49,6 +51,10 @@ const validateSubmission = async (
     await navigateAndValidateViewPage(page, thisStoreData);
     await validateFormData(page, 'viewPage', formDetails);
   }
+  if (thisStoreData.status === 'RECEIVED') {
+    logger(`Validating messaging for sent application with application ID: ${thisStoreData.applicationId}...`);
+    await validateMessaging(page, thisStoreData);
+  }
 }
 
 /**
@@ -424,6 +430,84 @@ const navigateAndValidateViewPage = async (
   logger('Draft validation on page:', viewPageURL);
 }
 
+/**
+ * The validateMessaging function.
+ *
+ * This function validates messaging after
+ * form submitting works as intended.
+ *
+ * @param page
+ *   Page object from Playwright.
+ * @param thisStoreData
+ *   The env form data.
+ */
+const validateMessaging = async (
+  page: Page,
+  thisStoreData: any
+) => {
+  const { applicationId } = thisStoreData;
+  const viewPageUrl = `/fi/hakemus/${applicationId}/katso`;
+
+  await page.goto(viewPageUrl);
+  await logCurrentUrl(page);
+  await page.waitForURL('**/katso');
+
+  const formActionButton = page.locator('form.grants-handler-message button.form-submit[name="op"]');
+  const textArea = page.locator('textarea[name="message"]');
+
+  // Validate error on empty message.
+  await formActionButton.click();
+  await page.waitForSelector('form.grants-handler-message .hds-notification--error');
+  await expect(page.locator('form.grants-handler-message .hds-notification--error')).toBeVisible();
+  await expect(page.locator('form.grants-handler-message .hds-notification--error .hds-notification__body')).toHaveText('1 virhe löytyi: Viesti');
+
+  // Validate sending message works.
+  await textArea.fill('Test message');
+
+  await formActionButton.click();
+  const responseBody = await getFulfilledResponse(page);
+  await expect(responseBody.length).toBe(4);
+
+  await page.waitForSelector('form.grants-handler-message .hds-notification--info');
+  const infoMessage = page.locator('form.grants-handler-message .hds-notification--info');
+  await expect(infoMessage).toBeVisible();
+  await expect(page.locator('form.grants-handler-message .hds-notification--info .hds-notification__body')).toContainText('Viestisi on lähetetty.');
+  await expect(formActionButton).toHaveText('Uusi viesti');
+
+  // Reload page to see message list.
+  await page.reload();
+  await page.waitForSelector('ul.webform-submission-messages__messages-list');
+
+  // Validate sending additional messages.
+  await textArea.fill('Test message 2');
+  await formActionButton.click();
+  const secondSubmitBody = await getFulfilledResponse(page);
+  expect(secondSubmitBody.length).toBe(4);
+  await page.waitForSelector('ul.webform-submission-messages__messages-list > h5');
+
+  const messages = await page.locator('.webform-submission-messages__messages-list .webform-submission-messages__message-body').all();
+  expect(messages.length).toEqual(2);
+  await expect(messages[0]).toContainText('Test message');
+  await expect(messages[1]).toContainText('Test message 2');
+
+  // Test adding attachment.
+  await formActionButton.click();
+  await textArea.fill('Attachment test message');
+  await uploadFile(
+    page,
+    'form.grants-handler-message .form-file',
+    'form.grants-handler-message .form-managed-file a',
+    ATTACHMENTS.MUU_LIITE,
+  );
+  await page.locator('input[name="attachmentDescription"]').fill('Attachment test description');
+  await formActionButton.click();
+
+  await expect(infoMessage).toBeVisible();
+  await expect(page.locator('form.grants-handler-message .hds-notification--info .hds-notification__body')).toContainText('Viestisi on lähetetty.');
+
+  logger('Message validation successful!');
+}
+
 /**
  * The navigateAndValidatePrintPage function.
  *