feat: mail provider backend

Signed-off-by: SebastianKrupinski <[email protected]>

lib/Provider/Command/MessageSend.php

@@ -86,15 +86,11 @@ public function perform(string $userId, string $serviceId, IMessage $message, ar
 			foreach ($message->getAttachments() as $entry) {
 				// convert mail provider attachment to mail app attachment
 				try {
-					$name = $entry->getName();
-					$type = $entry->getType();
-					$contents = $entry->getContents();
-
 					$attachments[] = $this->attachmentService->addFileFromString(
 						$userId,
-						$name,
-						$type,
-						$contents
+						(string)$entry->getName(),
+						(string)$entry->getType(),
+						(string)$entry->getContents()
 					)->jsonSerialize();
 				} catch (\Throwable $e) {
 					throw new SendException('Error: occurred while saving mail message attachment', 0, $e);
@@ -135,7 +131,7 @@ public function perform(string $userId, string $serviceId, IMessage $message, ar
 	 *
 	 * @param array<int,IAddress> $addresses collection of IAddress objects
 	 *
-	 * @return array<int,array{email?: string, label?: string}>
+	 * @return array<int, array{email: ?string, label?: ?string}>
 	 */
 	protected function convertAddressArray(array $addresses): array {
 		return array_map(static function (IAddress $address) {