Starting Point: you can use the parameter remove_files to remove the source files.

Removing files on FTP server

If the source is a FTP server then it is possible that you receive the following message in the log though the FTP user has write permission on the source files:

  INFO (SOSVfsFtpBaseClass.java:871) ::delete SOSVfs_I_131: File deleted : '/tmp/ftp/out/1.txt', reply is '550 Delete operation failed.

It is possible that the FTP server settings would not allow write operations.
Please check the FTP server settings.

Example configuration for FTP server (vsftpd)

You will find the settings in /etc/vsftpd.conf. Make sure that write_enabled=YES.

...
# ################
# General Settings
# ################
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES
#
...

See also