Cannot Write DAT File

I have sent a flat file through FTP to TN, and it gets recognised and stored into the Database.
The problem is when i send the document from TN to another Intergration through the Delivery Method … PRIMARY FTP, that i have specified in the Processing Rule,i get an error…
Delivery service for 5btdoc00v9the0ic0000004g failed with a status of fail and status message of 553 ‘5btdoc00v9the0gt0000004f.dat’: cannot write.

Please do the Needful

try putting the file as a .txt, that is set the extension on the remote file to .txt