EventHandler::onBeforeUpdateLetterTable

static function onBeforeUpdateLetterTable(MainEntity\Event $event, MainEntity\EventResult $result)
{
	$data = $event->getParameters();

	if (Bitrix24\Service::isCloud() && isset($data['fields']['STATUS']))
	{
		$oldRow = LetterTable::getRowById($data['primary']['ID']);
		$updatedBy = $data['fields']['UPDATED_BY'] ?? $oldRow['UPDATED_BY'];

		if (in_array($data['fields']['STATUS'], Dispatch\Semantics::getWorkStates()))
		{
			$user = new User($updatedBy);
			if (!$user->isAgreementAccepted())
			{
				$result->addError(
					new MainEntity\EntityError(Agreement::getErrorText(), 'NEED_ACCEPT_AGREEMENT')
				);
				return;
			}

			$letter = Entity\Letter::createInstanceById($data['primary']['ID']);

			if (is_null($letter))
			{
				$result->addError(
					new MainEntity\EntityError(
						Loc::getMessage("SENDER_LETTER_ONBEFOREUPDATE_ERROR_LETTER_NOT_AVAILABLE"), 'FEATURE_NOT_AVAILABLE'
					)
				);
				return;
			}

			if (!$letter->getMessage()->isAvailable())
			{
				if ($letter->getState()->isWaiting() || $letter->getState()->isSending())
				{
					$letter->stop();
				}

				$result->addError(
					new MainEntity\EntityError(
						Loc::getMessage("SENDER_LETTER_ONBEFOREUPDATE_ERROR_FEATURE_NOT_AVAILABLE"), 'FEATURE_NOT_AVAILABLE'
					)
				);
				return;
			}

			$isEmail = ($oldRow['MESSAGE_CODE'] === Message\iBase::CODE_MAIL);
			$isEmailBlocked = Bitrix24\Limitation\Rating::isBlocked();
			if ($isEmail && $isEmailBlocked)
			{
				$result->addError(
					new MainEntity\EntityError(
						Bitrix24\Limitation\Rating::getNotifyText('blocked')
					)
				);
			}

			if ($isEmail)
			{
				// check sender email:
				$emailFrom = $letter->getMessage()->getConfiguration()->getOption('EMAIL_FROM')->getValue();
				if (!Sender\AllowedSender::isAllowed($emailFrom, $updatedBy))
				{
					$result->addError(
						new MainEntity\EntityError(
							Loc::getMessage("SENDER_LETTER_ONBEFOREUPDATE_ERROR_INVALID_FROM_EMAIL"), 'WRONG_EMAIL_FROM'
						)
					);
				}
			}
		}
	}
}