[MM-41844] Warn cloud admin about workspace deletion at end of trial (#19672)

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/email/email_test.go

@@ -222,3 +222,41 @@ func TestSendCloudTrialEndWarningEmail(t *testing.T) {
 		verifyMailbox(t)
 	})
 }
+
+func TestSendCloudTrialEndedEmail(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+	th.ConfigureInbucketMail()
+
+	emailTo := "testclouduser@example.com"
+	emailToUsername := strings.Split(emailTo, "@")[0]
+
+	t.Run("SendCloudTrialEndedEmail", func(t *testing.T) {
+		verifyMailbox := func(t *testing.T) {
+			t.Helper()
+
+			var resultsMailbox mail.JSONMessageHeaderInbucket
+			err2 := mail.RetryInbucket(5, func() error {
+				var err error
+				resultsMailbox, err = mail.GetMailBox(emailTo)
+				return err
+			})
+			if err2 != nil {
+				t.Skipf("No email was received, maybe due load on the server: %v", err2)
+			}
+
+			require.Len(t, resultsMailbox, 1)
+			require.Contains(t, resultsMailbox[0].To[0], emailTo, "Wrong To: recipient")
+			resultsEmail, err := mail.GetMessageFromMailbox(emailTo, resultsMailbox[0].ID)
+			require.NoError(t, err, "Could not get message from mailbox")
+			require.Contains(t, resultsEmail.Body.Text, "your 14-day free trial of Mattermost Cloud Enterprise has ended today", "Wrong received message %s", resultsEmail.Body.Text)
+			require.Contains(t, resultsEmail.Body.Text, "we will delete your Cloud workspace permanently", "Wrong received message %s", resultsEmail.Body.Text)
+		}
+		mail.DeleteMailBox(emailTo)
+
+		err := th.service.SendCloudTrialEndedEmail(emailTo, emailToUsername, "June 23, 2200", th.BasicUser.Locale)
+		require.NoError(t, err)
+
+		verifyMailbox(t)
+	})
+}