Automatic Backup - Automatic FTP downloading

Dear DH users,

I’ve followed the instructions of the following tutorial:

And everything works fine except I’m unable to delete the archives after downloading them to my company’s server, im getting the following error:
ftp> mdelete archives/
200 Type set to I
550 Access is denied.

I’hv created a test file with 777 permission but yet still getting this problem?

Could the problem be from our ISA server?