In SQL Server 2000 the @Attachments parameter for the xp_SendMail stored procedure allowed you to pass attachments in the format "\\servername\sharename\filename;\\servername\sharename\filename;". However, when using the sp_Send_DBMail stored procedure @file_attachments parameter this format is invalid resulting in the error message:
The format of the parameter @attachments is incorrect. The file names must be separated by a semicolon ";".
Note also the incorrect naming of the parameter @file_attachments as @attachments. Instead you need to use the format "\\servername\sharename\filename;\\servername\sharename\filename".