| UpdateItems(IEnumerableItem, FolderId, ConflictResolutionMode, NullableMessageDisposition, NullableSendInvitationsOrCancellationsMode) | Updates multiple items in a single EWS call. UpdateItems does not support items that have unsaved attachments. |
| UpdateItems(IEnumerableItem, FolderId, ConflictResolutionMode, NullableMessageDisposition, NullableSendInvitationsOrCancellationsMode, Boolean, CancellationToken) | Updates multiple items in a single EWS call. UpdateItems does not support items that have unsaved attachments. |