Decryption problem

[Frank Yip]

I have a serious problem now. I have an application which will first encrypt
a file with specific recipient and upload to a ftp server in first day. Then
in second day, the same program will run and it will download the encrypted
file (first day uploaded file) if certain situation is not happend. Then it
will try to decrypt the file. In the past it works fine because the program
use DES. The problem now is as the file is encrypted with specific
recipient. I can't decrypt the encrypted file which is encrypted by me in
the second day as I am not the recipient. Is there any way to make this work
by allowing me (the sender) to decrypt the file which is encrypted by me??