SFTP sender channel : File processing @ Error :Error while sending message: Message ID XXXXXXXXX... already exists in database

Hi Experts,

I am testing File to File interface,SFTP sender channel shows the following error while its trying to reprocess the same file in the specified path.And  file is placed at receiver end for every poll interval. (But for the first time i din`t get any error in file picking.)

"Error while sending message: Message ID XXXXXXXXXXX....XXXX already exists in database: com.sap.sql.exception.OpenSQLIntegrityConstraintViolationException: ORA-00001: unique constraint (SAPSR3DB.I_XI_ID_MAP_ID1) violated OpenSQLExceptionCategories: [NON_TRANSIENT, INTEGRITY_CONSTRAINT_VIOLATION] "

Can anybody let me know why this file is not processed for the next interval...?

Is there any possibility to process the duplicate files through Sender SFTP ...?

Thanks

Dhileep