Large file handling SFTP-PROXY - SAP PI

Hi,

Scenario:

SFTP (FCC) -> PI (mapping) -> PROXY

Flat file (size 7-10MB, sometimes max 25MB) coming from SFTP is converted to XML via FCC. Then routed to mapping and sent to ECC via proxy.

I am getting error while transmission like "Failed to call the endpoint: null .... Unable to contact target server <host>.com:8000." But the server is active. This is happening every week (this interface will run weekly once). Flat file lines = 60000 - 75000 lines. I will be splitting it to 30000 lines into 2 files and will be loading in PI via SEND TEST MESSAGE. It took 3-4mins to process and got delivered.

Every time I am processing the file manually. Is there any way to solve this issue ?