Encryption details:

The setup program takes the random characters that you have entered and XORs each byte with a value returned by the rand() function seeded with the system clock time shortly after setup.exe was run. This process is intended to increase the spread of the nubers rather than to introduce any extra randomness to the key. The result is saved in the bfkey.dat file. When Delta Mail is run, the blowfish algorithm is initialised with the key contained within this file. Data which is to be encrypted is padded as per RFC 2630 with between 1 (1*0x01) and 8 (8*0x08) bytes so that the total length is a multiple of eight. The data is then encrypted with the blowfish algorithm and then base 64 encoded so that it can be transported by SMTP.