sp_send_dbmail & varbinary

EXEC msdb.dbo.sp_send_dbmail
@profile_name = 'SQL Mail Profile',
@recipients = 'emailaddress',
@query = 'set nocount on; select CAST(content AS varchar(MAX)) from files where fileid=''xxx''' ,
@subject = 'Random File',
@attach_query_result_as_file = 1,
@query_attachment_filename = 'random file.pdf',
@query_result_no_padding = 1,
@query_result_header = 0,
@query_no_truncate = 1;